CN106643191A - Power generation system based on steel smelting furnace and steel rolling heating furnace waste heat integration - Google Patents

Abstract

The invention discloses a power generation system based on waste heat integration of a steelmaking furnace and a steel rolling heating furnace, comprising a steelmaking furnace waste heat recovery device, a steel rolling heating furnace bottom water beam vaporization cooling device, a steel rolling heating furnace tail flue gas waste heat recovery flue, High-pressure drum, low-pressure drum-deaerator, steam turbine, generator, saturated steam generated by waste heat recovery device of steelmaking furnace, saturated steam generated by vaporization cooling device of bottom water beam of steel rolling heating furnace, waste heat recovery of flue gas at the tail of steel rolling heating furnace The saturated steam generated by the flue gathers into the superheater in the flue gas waste heat recovery flue at the tail of the steel rolling heating furnace. The steam outlet of the superheater is connected to the steam turbine, and the steam turbine is connected to the generator. The steam turns the steam turbine to do work, thereby driving the generator to generate electricity . The present invention comprehensively utilizes the waste heat of the steelmaking furnace and the steel rolling heating furnace. Compared with the conventional independent mode of utilizing the waste heat of the steelmaking furnace and the steel rolling heating furnace, the thermal system is more compact, the layout is finer, and the investment cost is lower.

Description

A power generation system based on waste heat integration of steelmaking furnace and steel rolling heating furnace

technical field

The invention relates to the technical field of energy saving in the iron and steel industry, in particular to a power generation system based on waste heat integration of a steelmaking furnace and a steel rolling heating furnace.

Background technique

Iron and steel enterprises have a lot of waste heat and waste energy resources in the smelting process. In recent years, various iron and steel enterprises have gradually paid attention to the recycling of waste heat resources in steel plants, and achieved certain results. However, since engineering construction is generally split construction, each process is separated and independent when subcontracted, and the process system of each process may have been optimized, but because the systems between the various smelting processes are not coordinated, each The lack of integrated optimization and overall layout of the waste heat resources in the process leads to the unoptimized utilization of energy, resulting in a certain degree of energy loss. As iron and steel enterprises pay more and more attention to energy saving and emission reduction, how to integrate and couple the waste heat system between the various processes in the steel plant to realize the overall optimization of the waste heat utilization system in the steel plant and improve the comprehensive utilization efficiency of waste heat resources has become a major issue for steelmaking enterprises. growing concern.

Among the various smelting processes in the steel plant, the steelmaking process and the steel rolling process are two adjacent processes, but the waste heat utilization systems up to now are all set up separately, and there is no comprehensive utilization of the waste heat of the steelmaking furnace and the steel rolling heating furnace.

Contents of the invention

The present invention intends to build a power generation system based on the integration of waste heat of steelmaking furnace and steel rolling heating furnace. The waste heat resources of steelmaking furnace and steel rolling heating furnace are integrated and optimized, which can generate considerable economic benefits and have important advantages. practical meaning.

According to one aspect of the present invention, a power generation system based on the integration of waste heat of steelmaking furnace and steel rolling heating furnace is provided, including a steelmaking furnace waste heat recovery device 1, a steel rolling heating furnace bottom water beam vaporization cooling device 9, and a steel rolling heating furnace tail Flue gas waste heat recovery flue 4, heat accumulator 2, steam turbine 10, generator 11, wherein, the flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace is arranged in the air preheating device of the steel rolling heating furnace along the flue gas flow And after the gas preheating device, the intermittent steam generated by the waste heat recovery device 1 of the steelmaking furnace is processed by the heat accumulator to form stable steam, which enters the superheater 41 arranged in the flue gas waste heat recovery flue at the tail of the steel rolling heating furnace, and the bottom of the steel rolling heating furnace The saturated steam produced by the water beam vaporization cooling device 9 and the saturated steam produced by the flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace are collected into the superheater 41, and the steam outlet of the superheater 41 is connected with the steam turbine 10, and the steam turbine is connected with the steam turbine 10. The generator 11 is connected, and the steam turns the steam turbine to do work, thereby driving the generator to generate electricity.

Preferably, a superheater 41, a high-pressure evaporator 42, a high-pressure economizer 43, a low-pressure evaporator 44, and a low-pressure economizer 45 connected in sequence are arranged in the flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace, wherein , the low-pressure drum-deaerator 5 communicates with the water inlet of the feedwater pump 6 through the water outlet pipe 53, the water outlet of the feedwater pump communicates with the water inlet of the high-pressure economizer 43, and the high-pressure economizer 43 passes through The pipeline 75 supplies water to the high-pressure drum 7, and the high-pressure drum 7 communicates with the water inlet of the high-pressure evaporator 42 through the first downcomer 71, and the steam outlet of the high-pressure evaporator is connected with the high-pressure cooker through the first riser 74. The rising nozzle of cylinder 7 is connected to form a natural steam-water circulation loop; high-pressure boiler cylinder 7 is connected to the water inlet of hot water circulation pump 8 through the second downcomer 72, and the water outlet of said hot water circulation pump is connected to the steel rolling heating furnace. The water inlet of the bottom water beam vaporization cooling device 9 is connected, and the steam outlet of the furnace bottom water beam vaporization cooling device 9 of the steel rolling heating furnace is communicated with the rising nozzle of the high-pressure drum 7 through the second rising pipe 73 to form a steam-water forced circulation loop, and the saturated steam produced by the high-pressure drum 7, the stable steam produced by the waste heat recovery device 1 of the steelmaking furnace and treated by the heat accumulator are collected in the steam main pipe 3, and the steam outlet of the steam main pipe and the superheater connected.

Preferably, the low-pressure drum-deaerator 5 communicates with the water inlet of the low-pressure evaporator 44 through the third downcomer 52, and the steam outlet of the low-pressure evaporator 44 communicates with the low-pressure boiler through the third riser 54. The riser nozzle of the barrel-deaerator 5 is connected to form a natural circulation loop of steam and water.

Preferably, the steam exhaust port of the steam turbine 10 communicates with the condenser 12 and the water inlet of the condensed water pump 13 in sequence along the steam-water flow, wherein the condensed water pipeline of the water outlet of the condensed water pump 13 is divided into two paths, and one path is connected with the condensed water pump 13. The water inlet of the waste heat recovery device 1 of the above-mentioned steelmaking furnace is connected, and the other path enters the low-pressure drum-deaerator 5 after being preheated by the low-pressure economizer 45 .

Preferably, a branch pipe 55 is branched from the steam main pipe 3 , which communicates with the auxiliary heating steam interface of the low-pressure drum-deaerator 5 .

Preferably, the superheater, high-pressure evaporator, high-pressure economizer, low-pressure evaporator, and low-pressure economizer are all arranged in countercurrent.

Preferably, the flue gas waste heat recovery flue at the tail of the steel rolling heating furnace is a flue with a built-in heat exchange surface or an integrated waste heat boiler.

Description of drawings

The above features and technical advantages of the present invention will become clearer and easier to understand by describing its embodiments in conjunction with the following drawings.

Fig. 1 is a schematic diagram showing a power generation system based on waste heat integration of a steelmaking furnace and a steel rolling heating furnace according to an embodiment of the present invention.

Among them, steelmaking furnace waste heat recovery device 1, regenerator 2, steam main pipe 3, flue gas waste heat recovery flue 4 at the tail of steel rolling heating furnace, superheater 41, high-pressure evaporator 42, high-pressure economizer 43, low-pressure evaporator 44. Low-pressure economizer 45, low-pressure drum-deaerator 5, feed water pump 6, high-pressure drum 7, hot water circulation pump 8, steel rolling heating furnace bottom water beam vaporization cooling device 9, steam turbine 10, generator 11, Condenser 12, condensate pump 13, first downcomer 71, second downcomer 72, second upcomer 73, first upcomer 74, pipeline 75, pipeline 51, third downcomer 52, outlet pipe 53, the first Three risers 54.

detailed description

Embodiments of the power generation system based on the integration of waste heat of the steelmaking furnace and the steel rolling heating furnace according to the present invention will be described below with reference to the accompanying drawings. Those skilled in the art would recognize that the described embodiments can be modified in various ways or combinations thereof without departing from the spirit and scope of the invention. Accordingly, the drawings and description are illustrative in nature and not intended to limit the scope of the claims. Also, in this specification, the drawings are not drawn to scale, and like reference numerals denote like parts. It should be noted that the high pressure and low pressure are named to distinguish the two pressure levels of the steam-water system (such as: the pressure of high-pressure steam and low-pressure steam are designed to be 1.6MPa and 0.5MPa respectively), not the absolute high pressure (such as 9.81 MPa), absolute low pressure (such as 0.8MPa), and the flow direction of the following steam and water flows in the direction shown by the arrow in the figure.

In view of the favorable condition that the main steelmaking workshop and the main steel rolling workshop are close to each other, the present invention optimizes and integrates the waste heat resources of the steelmaking furnace and the steel rolling heating furnace, and constructs a power generation system based on the integration of the waste heat of the steelmaking furnace and the steel rolling heating furnace. The invention is especially suitable for the situation that the steel rolling heating furnace uses gas with high calorific value, or the situation that the proportion of gas with high calorific value is high. Due to the high calorific value of gas, the preheating temperature required for both air and gas is not very high, and even the air only needs to be preheated without preheating the gas, so that the temperature of the flue gas after the air (or gas) preheating device is relatively high . The power generation system based on the waste heat integration of steelmaking furnace and steel rolling heating furnace mainly includes steelmaking furnace waste heat recovery device 1, steel rolling heating furnace bottom water beam vaporization cooling device 9, flue gas waste heat recovery flue 4 at the tail of steel rolling heating furnace, steam turbine 10, Generator 11. The waste heat recovery device of the steelmaking furnace may be a waste heat recovery device of an electric furnace, or a waste heat recovery device of a converter or a waste heat recovery device of an electric converter. The saturated steam generated by the waste heat recovery device 1 of the steelmaking furnace, the saturated steam generated by the bottom water beam vaporization cooling device 9 of the steel rolling heating furnace, and the saturated steam generated by the flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace are collected, and then sent together into the superheater 41 arranged in the flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace for superheating treatment to obtain superheated steam, and finally send it to the steam turbine 10, the steam turbine is connected with the generator, and the steam turns the steam turbine unit to perform work The generator 11 is driven to generate electricity, and the waste heat integrated power generation of the steelmaking furnace and the steel rolling heating furnace is realized.

The specific technological process thereof will be described in detail below in conjunction with FIG. 1 . The waste heat recovery device 1 of the steelmaking furnace communicates with the heat accumulator 2 through a steam pipeline, and sends the intermittent steam generated by the waste heat recovery device 1 of the steelmaking furnace into the heat accumulator, and the steam outlet of the heat accumulator 2 Connected with the steam main pipe 3, the heat accumulator 2 is used to stabilize the steam and convert the intermittently generated saturated steam into continuously output saturated steam.

The flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace is arranged after the air preheating device and the gas preheating device of the conventional steel rolling heating furnace along the flue gas flow, for absorbing residual heat. A superheater 41, a high-pressure evaporator 42, a high-pressure economizer 43, a low-pressure evaporator 44, and a low-pressure economizer 45 are arranged in the flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace, which are sequentially connected along the flue gas flow. . In particular, the superheater, the high-pressure evaporator, the high-pressure economizer, the low-pressure evaporator, and the low-pressure economizer all adopt a countercurrent arrangement, which can obtain higher heat exchange efficiency.

The low-pressure drum-deaerator 5 is a combination of the low-pressure drum and the deaerator, the deaerator is installed above the low-pressure drum, and the low-pressure drum doubles as a deaerator water tank. The water outlet of the low-pressure drum-deaerator 5 communicates with the water inlet of the feedwater pump 6 through the water outlet pipe 53 , and the water outlet of the feedwater pump communicates with the water inlet of the high-pressure economizer 43 . The water outlet of the high-pressure economizer 43 communicates with the water inlet of the high-pressure drum 7 through a pipeline 75 to supply water to the high-pressure drum 7 . The high-pressure drum 7 communicates with the water inlet of the high-pressure evaporator 42 through the first downcomer 71, and the steam outlet of the high-pressure evaporator 42 communicates with the riser nozzle of the high-pressure drum 7 through the first riser 74, forming Soda water natural circulation loop.

The high-pressure drum 7 communicates with the water inlet of the hot water circulation pump 8 through the second downcomer 72, and the water outlet of the hot water circulation pump communicates with the water inlet of the furnace bottom water beam vaporization cooling device of the rolling heating furnace. The steam outlet of the water beam vaporization cooling device at the bottom of the steel rolling heating furnace communicates with the rising nozzle of the high-pressure drum 7 through the second rising pipe 73 to form a steam-water forced circulation loop. The steam generated by the high-pressure drum 7 is collected into the steam main pipe 3 through the pipeline 76 .

The steam main pipe 3 communicates with the superheater 41, the steam turbine 10, the condenser 12 and the condensed water pump 13 in sequence along the steam-water flow, wherein the function of the superheater 41 is to transfer the saturated steam sent by the steam main pipe 3 The steam is converted into superheated steam, and the condenser 12 condenses the exhaust steam of the steam turbine 10 into condensed water, which is pressurized by the condensed water pump 13 and sent to the water inlet of each waste heat recovery device, specifically, the condensed water pump 13 The outlet condensate pipeline is divided into two paths, one path is connected with the water inlet of the waste heat recovery device 1 of the steelmaking furnace, and the other path is connected with the water inlet of the low-pressure economizer 45 . The water outlet of the low-pressure economizer 45 communicates with the water inlet of the low-pressure drum-deaerator 5 through a pipeline 51 .

The low-pressure drum-deaerator 5 communicates with the water inlet of the low-pressure evaporator 44 through the third downcomer 52, and the steam outlet of the low-pressure evaporator 44 communicates with the low-pressure drum-deaerator through the third riser 54. The riser nozzle of the oxygen device is connected to form a natural circulation loop.

In addition, a branch pipe 55 is branched from the steam main pipe 3 , which communicates with the auxiliary heating steam interface of the low-pressure drum-deaerator 5 .

In addition, the condenser is provided with a water supply port to supplement steam water lost in the waste heat recovery system.

In addition, the flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace is located downstream of the outlet flue of the steel rolling heating furnace, and the flue gas waste heat recovery flue 4 at the tail of the steel rolling heating furnace can be a common flue, and it Provide heat exchange surfaces, which can also be integrated waste heat boilers.

To sum up, the power generation system based on the waste heat integration of the steelmaking furnace and the steel rolling heating furnace of the present invention has the following beneficial effects:

(1) Compared with the conventional method in which the waste heat recovery of the steelmaking furnace and the steel rolling heating furnace is independently set, the present invention realizes the centralized utilization of the waste heat of the steelmaking furnace and the steel rolling heating furnace through system integration, and the whole thermal system is more compact and the layout is more refined. The investment cost is lower; in addition, for the saturated steam produced by the waste heat recovery of the steelmaking furnace, the present invention realizes the superheating of the waste heat saturated steam of the steelmaking furnace, compared with the conventional saturated steam of the steelmaking furnace waste heat, only the saturated steam power generation method can be used In comparison, it can not only improve the operating efficiency of the steam turbine, but also improve the working environment of the steam turbine (increase the steam dryness), and prolong the service life of the steam turbine blades.

(2) For the waste heat resources of the steel rolling heating furnace, the present invention integrates the vaporization cooling system of the bottom water beam of the steel rolling heating furnace and the flue gas waste heat recovery system at the tail of the steel rolling heating furnace, and unifies the layout, and adopts the vaporization cooling of the bottom water beam of the steel rolling heating furnace The device shares the drum and deaerator with the flue gas waste heat recovery device at the tail of the steel rolling heating furnace, which is significantly simplified compared with the conventional waste heat recovery mode of the steel rolling heating furnace, and the total investment is greatly reduced; in addition, the bottom water of the steel rolling heating furnace When optimizing the design of the beam vaporization cooling system and the flue gas waste heat recovery system at the tail of the steel rolling heating furnace, the steam water circulation system is designed as a natural circulation + forced circulation in combination with the respective characteristics of the bottom water beam vaporization cooling of the heating furnace and the waste heat recovery of the tail flue. The compound cycle method takes into account the energy-saving operation of the system under the condition of ensuring the safety and reliability of the system; the design of the whole set of waste heat power generation system and the connection relationship between each equipment are all optimized after the safety and thermal economy of the comprehensive system layout.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. a kind of based on converter and the integrated electricity generation system of heater for rolling steel waste heat, including converter waste-heat recovery device (1), Heater for rolling steel furnace bottom water beam apparatus for vapour-cooling (9), heater for rolling steel tail flue gas waste heat reclaiming flue (4), storage heater (2), steam turbine (10), generator (11), wherein,

The heater for rolling steel tail flue gas waste heat reclaiming flue (4) is pre- along the air that flue gas flow is arranged on heater for rolling steel After thermal and arrangement for gas preheating,

The intermediate steam that converter waste-heat recovery device (1) is produced forms stable steam Jing after storage heater process and enters to be arranged on and rolls Superheater (41) in steel heater tail flue gas waste heat reclaiming flue,

Saturated vapor and heater for rolling steel tail flue gas waste heat that heater for rolling steel furnace bottom water beam apparatus for vapour-cooling (9) is produced The saturated vapor for reclaiming flue (4) generation collects into the superheater (41),

The venthole of superheater (41) is connected with steam turbine (10), and the steam turbine is connected with the generator (11), steam punching Turn Steam Turbine acting, so as to drive electrical power generators.

2. according to claim 1 based on converter and the integrated electricity generation system of heater for rolling steel waste heat, the steel rolling adds Superheater (41), high pressure evaporator (42), the high pressure province for sequentially connecting is provided with hot stove tail flue gas waste heat reclaiming flue (4) Coal device (43), low pressure evaporator (44) and low-pressure coal saver (45), wherein,

Low pressure drum-oxygen-eliminating device (5) is connected by outlet pipe (53) with the water inlet of feed pump (6), the water outlet of the feed pump Mouth is connected with the water inlet of the high-pressure economizer (43), and the high-pressure economizer (43) is by pipeline (75) to the pressure cooker Cylinder (7) supplies water,

High pressure drum (7) is connected by the first down-comer (71) with the water inlet of the high pressure evaporator (42), and the high pressure steams The venthole for sending out device is connected by the first tedge (74) with the rising mouth of pipe of the high pressure drum (7), is formed carbonated drink and is followed naturally Loop back path；

High pressure drum (7) is connected by the second down-comer (72) with the water inlet of hot water circulating pump (8), the hot water circulating pump Delivery port is connected with the water inlet of heater for rolling steel furnace bottom water beam apparatus for vapour-cooling (9), the heater for rolling steel furnace bottom The venthole of water beam apparatus for vapour-cooling (9) is connected by the second tedge (73) with the rising mouth of pipe of the high pressure drum (7), Carbonated drink forced circulation loop is formed,

And high pressure drum (7) produce saturated vapor, converter waste-heat recovery device (1) produce and Jing storage heater process after it is steady Determine steam to be pooled in steam main (3), the venthole of the steam main is connected with superheater.

3. according to claim 2 based on converter and the integrated electricity generation system of heater for rolling steel waste heat, low pressure drum-remove Oxygen device (5) is connected by the 3rd down-comer (52) with the water inlet of the low pressure evaporator (44), the low pressure evaporator (44) Venthole connected with the rising mouth of pipe of the low pressure drum-oxygen-eliminating device (5) by the 3rd tedge (54), formed carbonated drink nature Closed circuit.

4. according to claim 2 based on converter and the integrated electricity generation system of heater for rolling steel waste heat, steam turbine (10) Steam drain sequentially connect along carbonated drink flow process with the water inlet of condenser (12), condensate pump (13), wherein,

The condensing water conduit of condensate pump (13) delivery port is divided into two-way, all the way with the converter waste-heat recovery device (1) water inlet connection, another road is entered in low pressure cooker cylinder-oxygen-eliminating device (5) Jing after low-pressure coal saver (45) preheating.

5. according to claim 2 based on converter and the integrated electricity generation system of heater for rolling steel waste heat, the steam is female A bypass line (55) is separated on pipe (3), is connected with the auxiliary heating vapor interface of the low pressure drum-oxygen-eliminating device (5).

6. according to claim 2 based on converter and the integrated electricity generation system of heater for rolling steel waste heat, the superheater, High pressure evaporator, high-pressure economizer, low pressure evaporator, low-pressure coal saver adopt counter-flow arrangement.

7. according to claim 1 based on converter and the integrated electricity generation system of heater for rolling steel waste heat,

The heater for rolling steel tail flue gas waste heat reclaiming flue is the flue or integrated waste heat boiler of built-in heat-transfer surface.