A walking beam heating furnace vaporization cooling system

Abstract

The present invention relates to a walking beam type heating furnace vaporization cooling system, which belongs to the technical field of heating furnace waste heat recovery. It comprises a water supply tank, an electric water supply pump, a water preheater, a pressure deaerator and a steam drum arranged below the pressure deaerator, which are connected in series in sequence through pipelines according to the flow direction; the steam drum is connected in series with an electric circulation pump through a descending pipeline led from the steam drum, and the electric circulation pump is connected in series with the heating furnace water beam and the water preheater in sequence according to the flow direction through an ascending pipeline led from the electric circulation pump, and then connected in series to the steam drum to form a circulation loop. The system has a simple structure, flexible layout, small footprint, and is energy-saving and economical; a pressure deaerator arranged above the steam drum is used to replace the traditional atmospheric thermal deaerator, which saves space and improves the deoxidation effect; the water preheater is introduced into the circulation loop, and the steam-water mixture converted from the circulating water is used to heat the water supply, thereby reducing the energy consumption of the pressure deaerator and further enhancing the deoxidation effect.

Description

Technical Field

[0001] The invention belongs to the technical field of waste heat recovery of heating furnaces and relates to a vaporization cooling system of a walking beam type heating furnace. Background Art

[0002] Heating furnace vaporization cooling technology is currently the most commonly used technology for water beam cooling of walking beam heating furnaces. It has the advantages of low water consumption, long water beam service life, and generation of recyclable steam. Figure 1 The figure shows a schematic diagram of the layout of the existing walking beam type heating furnace vaporization cooling system. The working process of the system is as follows: the make-up water (soft water or desalted water) from the plant area make-up water network enters the make-up water tank 1, is pressurized by the electric make-up water pump 2 and then sent to the atmospheric thermal deaerator 3 for deoxygenation, the deoxygenated make-up water enters the deoxygenation water tank 4, is pressurized by the electric feed water pump 5 and then sent to the steam drum 6, and is mixed with the circulating water in the steam drum 6. The mixed circulating water reaches the electric circulating pump 7 through the circulating water descending pipe 9, is pressurized by the electric circulating pump 7 and then sent to the heating furnace water beam 8, the heating furnace water beam 8 is cooled, the circulating water itself is heated to become a steam-water mixture, is sent to the steam drum 6 through the circulating water ascending pipe 10, and steam-water separation is carried out in the steam drum 6. The separated water continues to circulate through the electric circulating pump 7, a part of the separated steam is sent to the atmospheric thermal deaerator 3 to heat the make-up water, and the other part is sent to the plant area steam network.

[0003] The existing walking beam heating furnace vaporization cooling system has the following main disadvantages:

[0004] (1) The system is complex. This is mainly reflected in the fact that the system is equipped with both an electric water replenishment pump 2 and an electric water supply pump 5, and a deaeration water tank 4 is also separately set under the atmospheric thermal deaerator 3. The system has many pipelines and control parameters.

[0005] (2) High layout requirements. The feed water temperature after deoxygenation by the atmospheric thermal deaerator 3 exceeds 100°C (such as reaching 104°C). In order to avoid cavitation of the electric feed water pump 5, the atmospheric thermal deaerator 3 and the electric feed water pump 5 need to be installed at a height difference of at least 6m.

[0006] (3) Large footprint, high investment, and high operating costs. The system is complex and has high layout requirements, resulting in a large footprint and high investment for the entire system. The system is equipped with both an electric water replenishment pump 2 and an electric water supply pump 5, which consumes a lot of electricity and has high operating costs.

[0007] (4) Poor deoxygenation effect. The system uses an atmospheric thermal deaerator 3, which has a low working pressure (only 0.02MPa), which is much different from the working pressure of the steam drum 6 (generally 0.5MPa to 1.6MPa), resulting in poor deoxygenation effect. The oxygen content of the make-up water after deoxygenation is still high, and the equipment and pipelines in the system are susceptible to oxygen corrosion. Summary of the invention

[0008] In view of this, the object of the present invention is to provide a walking beam type heating furnace vaporization cooling system with simple structure, flexible layout, small footprint, energy saving and economy, so as to solve the problems of the existing walking beam type heating furnace vaporization cooling system, such as complex system, high layout requirements, large footprint, high investment, high operating cost and poor deoxidation effect.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] A walking beam type heating furnace vaporization cooling system comprises a water makeup tank, an electric water supply pump, a water preheater, a pressure deaerator and a steam drum arranged below the pressure deaerator, which are connected in series in sequence through pipelines according to flow direction; the steam drum is connected in series with an electric circulation pump through a descending pipeline led from the steam drum, and the electric circulation pump is connected in series with the heating furnace water beam and the water preheater in sequence according to flow direction through an ascending pipeline led from the electric circulation pump, and then connected in series to the steam drum to form a circulation loop.

[0011] Furthermore, a bypass pipe leading to the steam drum is connected to the pipe leading from the electric feed water pump to the water preheater, and a first shut-off valve is provided in the section from the connection point to the water preheater; a second shut-off valve is provided on the pipe leading from the water preheater to the pressure deaerator, a third shut-off valve is provided on the bypass pipe, and a fourth shut-off valve is provided on the pipe leading from the pressure deaerator to the steam drum.

[0012] Furthermore, the electric water supply pump is arranged on the horizontal side or below the water supply tank.

[0013] Furthermore, there is at least one heating furnace water beam.

[0014] Furthermore, when there are multiple water beams of the heating furnace, they are connected in series or in parallel.

[0015] Furthermore, the water supply tank is provided with a pipeline connected to the water supply network of the factory area.

[0016] Furthermore, the steam drum is provided with a pipeline connected to the steam network of the factory.

[0017] The beneficial effects of the present invention are:

[0018] (1) The walking beam heating furnace vaporization cooling system disclosed in the present invention eliminates the electric water supply pump, deaeration water tank and other equipment and the corresponding pipelines and control systems, making the system more streamlined as a whole, reducing the floor space, saving investment and making the operation more economical.

[0019] (2) The walking beam type heating furnace vaporization cooling system disclosed in the present invention has normal temperature water as the make-up water entering the electric feed water pump, and there is no problem of cavitation of the electric feed water pump caused by high temperature make-up water vaporization. There is no strict restriction on the installation height difference between the electric feed water pump and the make-up water tank, and the layout is flexible. The electric feed water pump can be arranged on the same floor as the make-up water tank, set on the horizontal side of the make-up water tank, or arranged below the make-up water tank, further reducing the floor space; this system uses a pressure deaerator, which is arranged above the steam drum, which also reduces the floor space.

[0020] (3) In the walking beam type heating furnace vaporization cooling system disclosed in the present invention, the working pressure of the pressure deaerator is consistent with the working pressure of the steam drum, and the deoxygenation effect is good. In addition, a water preheater is introduced and arranged at the node of the circulation loop, and the feed water is preheated by using the steam-water mixture converted from the circulating water, and then sent to the pressure deaerator, thereby reducing the heating temperature difference of the feed water in the pressure deaerator, reducing the heating energy consumption of the pressure deaerator for the feed water, and further enhancing the deoxygenation effect. Without the need to increase the external heat source, the oxygen corrosion of the equipment and pipelines in the system is reduced, and the service life of the system is extended.

[0021] (4) In the walking beam type heating furnace vaporization cooling system disclosed in the present invention, when the pressure deaerator fails, the pipeline between the electric water supply pump and the water preheater is connected to the bypass pipeline through the third shut-off valve, and other shut-off valves disconnect other corresponding pipelines. Make-up water can be sent to the steam drum through the bypass pipeline, which will not affect the normal production of the heating furnace and is convenient for the maintenance and replacement of the pressure deaerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention provides the following drawings for illustration:

[0023] Figure 1 It is a schematic diagram of the layout of the existing walking beam type heating furnace vaporization cooling system;

[0024] Figure 2 A schematic diagram of the layout of a vaporization cooling system for a walking beam heating furnace provided by the present invention.

[0025] Figure numerals: make-up water tank 1, electric make-up water pump 2, atmospheric thermal deaerator 3, deoxygenated water tank 4, electric feed water pump 5, steam drum 6, electric circulation pump 7, heating furnace water beam 8, downcomer 9, upcomer 10, pressure deaerator 11, water preheater 12, bypass pipe 13, first shut-off valve 14, second shut-off valve 15, third shut-off valve 16, fourth shut-off valve 17. DETAILED DESCRIPTION

[0026] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] like Figure 2As shown, this embodiment provides a walking beam type heating furnace vaporization cooling system, including a water supply tank 1, an electric water supply pump 5, a water preheater 12, a pressure deaerator 11 and a steam drum 6 arranged below the pressure deaerator 11, which are connected in series in sequence through pipelines according to the flow direction; the steam drum 6 is connected in series with an electric circulation pump 7 through a descending pipeline 9 drawn from the steam drum 6, and the electric circulation pump 7 is connected in series with the heating furnace water beam 8 and the water preheater 12 in sequence through an ascending pipeline 10 drawn from the electric circulation pump 7, and then connected in series to the steam drum 6 to form a circulation loop. There are two heating furnace water beams 8, which can be connected in series or in parallel with each other. In this embodiment, the two heating furnace water beams 8 are connected in parallel with each other. This system cancels the electric water supply pump 2, the deaeration water tank 4 and other equipment and the corresponding pipelines and control systems, making the system more streamlined as a whole, reducing the floor space, saving investment, and operating more economically.

[0028] In this system, the make-up water entering the electric feed water pump 5 is room temperature water, which will not cause cavitation to the electric feed water pump 5. Therefore, there is no strict requirement for the installation height difference between the electric feed water pump 5 and the make-up water tank 1. The electric feed water pump 5 can be installed on the horizontal side of the same level as the make-up water tank 1, or it can be installed below the make-up water tank 1 in the layout form disclosed in this embodiment, which can further reduce the occupied area and save space. The steam drum 6 is arranged below the pressure deaerator 11 to save space.

[0029] The water supply tank 1 is provided with a pipeline connected to the water supply network in the plant area; the steam drum 6 is provided with a pipeline connected to the steam network in the plant area. After the water supply (soft water or desalted water) from the water supply network in the plant area enters the water supply tank 1, it is pressurized by the electric water supply pump 5 and then sent to the water preheater 12 at the node of the circulation loop. The steam-water mixture converted from the circulating water is used to preheat the water supply. The preheated water supply is sent to the pressure deaerator 11 for deoxygenation. The deoxygenated water flows downward into the steam drum 6 and is mixed with the circulating water in the steam drum 6. The mixed circulating water reaches the electric circulating pump 7 through the descending pipe 9 and is sent to the heating furnace water beam 8 after being pressurized by the electric circulating pump 7. , the heating furnace water beam 8 is cooled, the circulating water itself is heated to become a steam-water mixture, and first reaches the water preheater 12 through the rising pipe 10 to preheat the make-up water from the electric feed water pump 5, and then enters the steam drum 6, and the steam and water are separated in the steam drum 6. The separated water continues to circulate through the electric circulating pump 7. Part of the separated steam is sent upward to the pressure deaerator 11 to heat the make-up water, and the other part is sent to the plant steam network through a pipeline arranged on the steam drum 6 and connected to the plant steam network.

[0030] As an improvement of the present embodiment, a bypass pipe 13 leading to the drum 6 is connected to the pipe leading from the electric feed water pump 5 to the water preheater 12, and a first shut-off valve 14 is provided in the section from the connection point to the water preheater 12; a second shut-off valve 15 is provided on the pipe leading from the water preheater 12 to the pressure deaerator 11, a third shut-off valve 16 is provided on the bypass pipe 13, and a fourth shut-off valve 17 is provided on the pipe leading from the pressure deaerator 11 to the drum 6. When the pressure deaerator 11 fails, the pipe between the electric feed water pump 5 and the water preheater 12 is connected to the bypass pipe 13 through the third shut-off valve 16, the first shut-off valve 14, the second shut-off valve 15 and the fourth shut-off valve 17 disconnect the corresponding pipes, and the make-up water can be sent to the drum 6 through the bypass pipe 13, which does not affect the normal production of the heating furnace, and the pressure deaerator 11 is also convenient for maintenance and replacement.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A walking beam heating furnace vaporization cooling system, characterized in that: It comprises a make-up water tank, an electric feed water pump, a water preheater, a pressure deaerator and a steam drum arranged below the pressure deaerator, which are connected in series in sequence through pipelines according to the flow direction; the steam drum is connected in series with an electric circulation pump through a descending pipeline led from the steam drum, and the electric circulation pump is connected in series with a heating furnace water beam and a water preheater in sequence according to the flow direction through an ascending pipeline led from the electric circulation pump, and then connected in series to the steam drum to form a circulation loop; a bypass pipeline leading to the steam drum is connected to the pipeline led from the electric feed water pump to the water preheater, and a first shut-off valve is provided in the section from the connection point to the water preheater; a second shut-off valve is provided on the pipeline led from the water preheater to the pressure deaerator, a third shut-off valve is provided on the bypass pipeline, and a fourth shut-off valve is provided on the pipeline led from the pressure deaerator to the steam drum.

2. The walking beam heating furnace vaporization cooling system according to claim 1, characterized in that: The electric water supply pump is arranged on the horizontal side or below the water supply tank.

3. The walking beam heating furnace vaporization cooling system according to claim 1 or 2, characterized in that: The heating furnace has at least one water beam.

4. The walking beam type heating furnace vaporization cooling system according to claim 3, characterized in that: When there are multiple water beams of the heating furnace, they are connected in series or in parallel.

5. The walking beam heating furnace vaporization cooling system according to claim 1, characterized in that: The water replenishment tank is provided with a pipeline connected to the water replenishment network of the factory area.

6. The walking beam heating furnace vaporization cooling system according to claim 1, characterized in that: The steam drum is provided with a pipeline connected to the steam network of the factory area.

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