CN103244940B - A kind of band is from the two pressure waste heat boiler of the medium temperature and medium pressure of deaerating type of cycles - Google Patents

Abstract

A kind of band is from the two pressure waste heat boiler of the medium temperature and medium pressure of deaerating type of cycles, be provided with boiler body, the platform of boiler body is provided with oxygen-eliminating device and boiler water-feeding device, boiler water-feeding device outlet is connected with oxygen-eliminating device, medium pressure steam system and steam vapour system is provided with in boiler body, boiler water-feeding device is supplied water to medium pressure steam system and steam vapour system by oxygen-eliminating device, present invention optimizes steam-water pipe technological process, heat-transfer surface is arranged and heat exchanger tube form, and echelon can utilize fume afterheat.

Description

A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system

technical field

The invention relates to a boiler used for a waste heat power generation device, in particular to a medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deoxidizing system.

Background technique

The iron and steel industry is a large energy consumer in my country, accounting for about 15% of the total energy consumption in the country. In the process of iron and steel production, the energy consumption of the sintering process ranks second, and the sensible heat of sintering production in sintering production accounts for more than 40% of the total heat consumption. Sintering energy saving is very important. Efficient recovery and utilization of sensible heat of sinter is an effective way to improve the energy efficiency of the iron and steel industry. Compared with the traditional belt-type or ring-cooled sintering machine waste heat power generation technology, there are inherent shortcomings such as large fluctuations in waste heat parameters, low waste heat flue gas temperature, and high self-consumption. , Reduce cooling power consumption, and the parameters of waste heat flue gas are stable, and the temperature can reach about 600 ℃, which is more conducive to the recovery and utilization of sinter waste heat. Therefore, the waste heat power generation technology of furnace-cooled sintering machine is the development direction of sintering machine waste heat utilization.

According to the characteristics of the waste heat parameters of the sinter furnace cold process, a high-efficiency waste heat boiler adapted to the parameters of the furnace cold flue gas is developed to maximize the efficiency and steam production of the waste heat boiler, thereby improving the waste heat power generation capacity and increasing the rate of return. The engineering promotion of waste heat power generation technology of sintering machine is of great significance.

Contents of the invention

The purpose of the present invention is to adapt to the waste heat parameters of the sinter furnace cold process, improve the utilization efficiency of waste heat, make full use of the waste heat discharged during the cooling process of sinter, and provide a medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system , the process flow of the steam-water pipeline, the layout of the heat exchange surface and the form of the heat exchange tube are optimized, and the waste heat of the flue gas can be utilized step by step.

The present invention is for solving the deficiencies of the above-mentioned technical problems, and the technical scheme adopted is:

A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system, equipped with a boiler body, a deaerator and a boiler water supply device are installed on the platform of the boiler body, the outlet of the boiler water supply device is connected to the deaerator, and the inside of the boiler body Equipped with a medium-pressure steam system and a low-pressure steam system, the boiler water supply device supplies water to the medium-pressure steam system and low-pressure steam system through the deaerator;

The medium-pressure steam system includes a medium-pressure feed pump, a medium-pressure economizer A, a medium-pressure economizer B, a medium-pressure steam drum, a medium-pressure evaporator, a medium-pressure superheater A, a spray desuperheater and a medium-pressure Pressure superheater B, the water in the main pipe of the deaerator passes through the medium-pressure feed water pump, then flows through the medium-pressure economizer A and the medium-pressure economizer B successively and enters the medium-pressure steam drum, and the medium-pressure steam drum The water in the medium-pressure steam drum flows into the medium-pressure evaporator and then returns to the medium-pressure steam drum. The steam in the medium-pressure steam drum flows out from the medium-pressure steam drum and flows through the medium-pressure superheater A, spray desuperheater and medium-pressure superheater in sequence. Device B, the medium pressure superheater B is connected with the medium pressure steam utilization device;

The low-pressure steam system includes a low-pressure feedwater pump, a low-pressure economizer, a low-pressure steam drum, a low-pressure evaporator and a low-pressure superheater. After the water in the main pipe of the deaerator passes through the low-pressure feedwater pump, the water flows through the low-pressure economizer into the low-pressure steam drum, the water in the low-pressure steam drum flows from the low-pressure steam drum into the low-pressure evaporator and returns to the low-pressure steam drum, the steam in the low-pressure steam drum flows out of the low-pressure steam drum, flows through the low-pressure superheater, and the low-pressure superheater Connect with low-pressure steam utilization device;

The medium pressure superheater B, medium pressure superheater A, medium pressure evaporator, low pressure superheater, medium pressure economizer B, low pressure evaporator, medium pressure economizer A, low pressure economizer and hot water exchange The heaters are arranged in sequence from the boiler inlet to the boiler outlet inside the boiler body.

The steam inlet end of the deaerator is connected with the low-pressure superheater.

The boiler water supply device includes a water supply device and a hot water heat exchanger, and the water supply device is connected to the deaerator after passing through the hot water heat exchanger.

The inlet of the water spray desuperheater is connected to the water supply device, and the outlet is connected to the outlet of the medium pressure superheater A.

The deaerator is an atmospheric thermal deaerator.

The boiler is of vertical structure.

The medium pressure superheater B, medium pressure superheater A, medium pressure evaporator, low pressure superheater, medium pressure economizer B, low pressure evaporator, medium pressure economizer A, low pressure economizer and hot water exchange Heaters are made of spiral finned tubes.

The beneficial effects of the present invention are as follows: 1. Adopting a dual-pressure system, the medium-pressure steam has a higher power generation capacity, and compared with the low-pressure steam produced by the traditional sintering machine waste heat boiler, the power generation capacity is increased by 15% to 20%. The low-pressure system can reduce the exhaust gas temperature of the boiler to about 100°C, and the efficiency of the waste heat boiler can reach about 80%. The temperature is basically kept stable, which is conducive to the safe and stable operation of the waste heat power generation system; 3. The heat exchange surface layout and pipe material in the waste heat boiler are optimized, the heat exchange end difference between flue gas and steam water is reduced, and the steam production of the boiler is increased; 4. The waste heat boiler adopts an atmospheric thermal deaerator, which has a stable deoxygenation effect, can effectively reduce the oxygen corrosion on the heat exchange surface of the boiler, and improve the service life of the boiler; the deaerator is arranged on the boiler platform, and the low-pressure superheated steam generated by the waste heat boiler replaces Steam turbine extraction is used for deoxygenation, which not only optimizes the steam-water process, but also reduces the steam extraction volume of the steam turbine and improves the power generation capacity of the steam turbine; 5. The waste heat boiler is designed with a hot water heat exchange surface, which can not only further reduce the exhaust gas temperature of the waste heat boiler , Improve the boiler efficiency, and can increase the temperature of the feed water entering the deaerator, reduce the steam consumption of the deaerator, and more low-pressure steam enters the steam turbine to generate electricity, which improves the power generation of the system.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Icon marks: 1. Boiler inlet; 2. Boiler outlet; 3. Water supply device; 4. Hot water heat exchanger; 5. Deaerator; 6. Medium pressure feed water pump; 7. Low pressure feed water pump; 8. Low pressure province 9. Medium pressure economizer A; 10. Low pressure evaporator; 11. Medium pressure economizer B; 12. Low pressure superheater; 13. Medium pressure evaporator; 14. Medium pressure superheater A; 15. Medium-pressure superheater B; 16. Low-pressure steam utilization device; 17. Medium-pressure steam utilization device; 18. Low-pressure steam drum; 19. Medium-pressure steam drum; 20. Water spray desuperheater; Steam inlet; 23. Boiler body.

Detailed ways

As shown in the figure, the specific implementation method is as follows:

A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system, equipped with a boiler body 23, a deaerator 5 and a boiler water supply device are provided on the platform of the boiler body 23, and the outlet of the boiler water supply device is connected to the deaerator 5 , the boiler body 23 is provided with a medium-pressure steam system and a low-pressure steam system, and the boiler water supply device supplies water to the medium-pressure steam system and the low-pressure steam system through the deaerator 5,

The medium-pressure steam system includes medium-pressure feed pump 6, medium-pressure economizer A9, medium-pressure economizer B11, medium-pressure steam drum 19, medium-pressure evaporator 13, medium-pressure superheater A14, water spray desuperheating 20 and medium-pressure superheater B15, the water in the main pipe of the deaerator 5 passes through the medium-pressure feed water pump 6, and then flows through the medium-pressure economizer A9 and medium-pressure economizer B11 to enter the medium-pressure steam drum 19. The water in the medium-pressure steam drum 19 flows from the medium-pressure steam drum 19 into the medium-pressure evaporator 13 and returns to the medium-pressure steam drum 19, and the steam in the medium-pressure steam drum 19 flows out from the medium-pressure steam drum 19, and flows through the medium-pressure Superheater A14, water spray desuperheater 20 and medium pressure superheater B15, medium pressure superheater B15 is connected with medium pressure steam utilization device 17;

The low-pressure steam system includes a low-pressure feedwater pump 7, a low-pressure economizer 8, a low-pressure steam drum 18, a low-pressure evaporator 10 and a low-pressure superheater 12, and the water in the main pipe of the deaerator 5 passes through the low-pressure feedwater pump 7 Finally, water flows through the low-pressure economizer 8 and enters the low-pressure steam drum 18, and the water in the low-pressure steam drum 18 flows into the low-pressure steam drum 10 from the low-pressure steam drum 18 and returns to the low-pressure steam drum 18, and the steam in the low-pressure steam drum 18 flows from the low-pressure steam drum Bag 18 flows out, flows through low-pressure superheater 12, and low-pressure superheater 12 is connected with low-pressure steam utilization device 16;

The medium pressure superheater B15, medium pressure superheater A14, medium pressure evaporator 13, low pressure superheater 12, medium pressure economizer B11, low pressure evaporator 10, medium pressure economizer A9, low pressure economizer 8 The hot water heat exchanger 4 is arranged in sequence from the boiler inlet 1 to the boiler outlet 2 inside the boiler body 23 .

The steam inlet end 22 of the deaerator 5 is connected with the low pressure superheater 12 .

The boiler water supply device includes a water supply device 3 and a hot water heat exchanger 4 , and the water supply device 3 is connected to a deaerator 5 after passing through the hot water heat exchanger 4 .

The inlet of the water spray desuperheater 20 is connected to the water supply device 3, and the outlet is connected to the outlet of the medium pressure superheater A14.

The deaerator 5 is an atmospheric thermal deaerator.

The boiler 23 adopts a vertical structure.

The medium pressure superheater B15, medium pressure superheater A14, medium pressure evaporator 13, low pressure superheater 12, medium pressure economizer B11, low pressure evaporator 10, medium pressure economizer A9, low pressure economizer 8 Both the heat exchanger 4 and the hot water heat exchanger adopt spiral finned tubes.

The water supply device 3 first enters the hot water heat exchanger 4 to absorb heat, the temperature rises to about 90°C and enters the deaerator head of the deaerator 5, and the chemical supplement water 21 of the power station system also enters the deaerator head of the deaerator 5, and The steam 22 required for oxygen removal in the deaerator 5 comes from the outlet of the low-pressure superheater 12, and the oxygen in the boiler feed water device and chemical make-up water 21 is removed in the deaerator 5.

The water in the main pipe of the deaerator enters the low-pressure economizer 8 for initial heating after being pressurized by the low-pressure feedwater pump 7, and the water from the low-pressure economizer 8 enters the low-pressure steam drum 19, and the saturated water in the low-pressure steam drum 19 enters the low After the evaporator 10 absorbs heat, it turns into a steam-water mixture and returns to the low-pressure steam drum 19. The saturated steam in the low-pressure steam drum 19 is heated by the low-pressure superheater 12 and then becomes a low-pressure superheated steam. Appliance steam 22.

The water in the main pipe of the deaerator is pressurized by the medium pressure feedwater pump 6 and then enters the medium pressure economizer A9 and the medium pressure economizer B11 for heating, and the water from the medium pressure economizer B11 enters the medium pressure steam drum 19 , the saturated water in the medium-pressure steam drum enters the medium-pressure evaporator 13 to absorb heat and turns into a steam-water mixture and returns to the medium-pressure steam drum 19. The saturated steam in the medium-pressure steam drum 19 is first heated by the medium-pressure superheater A14, sprayed The water desuperheater 20 is used to adjust the outlet steam temperature of the medium-pressure superheater A14. The spray water used comes from the boiler feed water 3, and the steam after water spraying and desuperheating enters the medium-pressure superheater B15 for heating and becomes medium-pressure superheated steam 17 External steam supply.

The technical solutions and implementation methods listed in the present invention are not limiting, and solutions that are equivalent to or have the same effect as the technical solutions and implementation methods listed in the present invention are within the protection scope of the present invention.

Claims (7)

1. A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system, equipped with a boiler body (23), a deaerator (5) and a boiler water supply device are installed on the platform of the boiler body (23), and the boiler water supply The outlet of the device is connected to the deaerator (5), which is characterized in that: the boiler body (23) is equipped with a medium-pressure steam system and a low-pressure steam system, and the boiler water supply device supplies water to the medium-pressure steam system and low-pressure steam system through the deaerator (5). system water supply, The medium-pressure steam system includes a medium-pressure feed water pump (6), a medium-pressure economizer A (9), a medium-pressure economizer B (11), a medium-pressure steam drum (19), a medium-pressure evaporator (13 ), medium pressure superheater A (14), spray desuperheater (20) and medium pressure superheater B (15), the water in the main pipe of the deaerator (5) passes through the medium pressure feed water pump (6 ), the water flows through the medium-pressure economizer A (9) and the medium-pressure economizer B (11) into the medium-pressure steam drum (19) in turn, and the water flows from the medium-pressure steam drum (19) into the medium-pressure evaporator (13) After returning to the medium-pressure steam drum (19), the water flows out from the medium-pressure steam drum (19), and flows through the medium-pressure superheater A (14), spray desuperheater (20) and medium-pressure superheater B (15) in sequence , the medium pressure superheater B (15) is connected with the medium pressure steam utilization device (17); The low-pressure steam system includes a low-pressure feed water pump (7), a low-pressure economizer (8), a low-pressure steam drum (18), a low-pressure evaporator (10) and a low-pressure superheater (12), and the deaerator ( 5) After the water in the main pipe passes through the low-pressure feed water pump (7), the water flows through the low-pressure economizer (8) into the low-pressure steam drum (18), and the water in the low-pressure steam drum (18) flows through the low-pressure evaporator (10 ) after returning to the low-pressure steam drum (18), water flows out from the low-pressure steam drum (18), flows through the low-pressure superheater (12), and the low-pressure superheater (12) is connected with the low-pressure steam utilization device (16); The medium pressure superheater B (15), medium pressure superheater A (14), medium pressure evaporator (13), low pressure superheater (12), medium pressure economizer B (11), low pressure evaporator ( 10), medium-pressure economizer A (9), low-pressure economizer (8) and hot water heat exchanger (4) are arranged in sequence from the boiler inlet (1) to the boiler outlet (2) inside the boiler body (23) set up. 2. A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system according to claim 1, characterized in that: the air inlet (22) of the deaerator (5) is connected to the low-pressure superheater ( 12) Connect. 3. A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system according to claim 1, characterized in that: the boiler water supply device includes a water supply device (3) and a hot water heat exchanger (4 ), the water supply device (3) is connected to the deaerator (5) after passing through the hot water heat exchanger (4). 4. A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system according to claim 1, characterized in that: the inlet of the water spray desuperheater (20) is connected to the water supply device (3), and the spray water The inlet of the water desuperheater (20) is connected with the medium pressure superheater A (14). 5. A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system according to claim 1 or 2, characterized in that: the deaerator (5) is an atmospheric thermal deaerator. 6. A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deoxidizing system according to claim 1, characterized in that: the boiler body (23) adopts a vertical structure. 7. A medium-temperature, medium-pressure, double-pressure waste heat boiler with a self-deaeration system according to claim 1, characterized in that: said medium-pressure superheater B (15), medium-pressure superheater A (14), Medium pressure evaporator (13), low pressure superheater (12), medium pressure economizer B (11), low pressure evaporator (10), medium pressure economizer A (9), low pressure economizer (8) and The hot water heat exchangers (4) all adopt spiral finned tubes.