Coke oven ascension pipe waste heat recovery system with controllable superheated steam temperature

Abstract

The utility model discloses a coke oven ascension pipe waste heat recovery system with a controllable superheated steam temperature. The coke oven ascension pipe waste heat recovery system comprises a desalting water tank, a desalting water pump, a deaerator, a steam pocket water feeding pump, a steam pocket, a forced circulation pump, an ascension pipe evaporator, an ascension pipe superheater, a superheated steam flow regulating valve, a spray desuperheater and a desuperheating water regulating valve, wherein the water outlet end of the desalting water tank is connected with the water inlet end of the desalting water pump, the water outlet end of the desalting water pump is connected with the water inlet end of the deaerator, the water outlet end of the deaerator is connected with the water inlet end of the steam pocket feed pump, and the water outlet end of the steam pocket feed pump is simultaneously connected with the water inlet ends of the two steam pockets which are arranged in parallel; the steam outlet ends of the two steam pockets are both connected with the steam inlet ends of the ascending pipe superheaters, the steam outlet ends of the ascending pipe superheaters are connected with the steam inlet ends of the water spraying desuperheaters, the steam outlet ends of the water spraying desuperheaters are connected with the user side, the number of the ascending pipe superheaters is two, and the ascending pipe superheaters are arranged in parallel. And the temperature of the superheated steam is kept stable.

Description

Technical Field

[0001] The utility model relates to the field of waste heat recovery of coke oven riser pipes with controllable superheated steam temperature. More specifically, the utility model relates to a waste heat recovery system of coke oven riser pipes with controllable superheated steam temperature. Background Art

[0002] The coke oven riser waste heat recovery system utilizes part of the sensible heat of the coke oven raw gas to produce saturated steam or superheated steam. Coking enterprises generally use coke oven gas as raw material to prepare and produce superheated steam in combination with a tubular furnace in the crude benzene distillation section of the recovery workshop. This production method will also produce pollutants such as NOx. The use of the coke oven riser waste heat recovery system to produce superheated steam can not only reduce the consumption of coke oven gas caused by the operation of tubular furnaces, but also reduce the emission of pollutants such as NOx.

[0003] However, the production of superheated steam by the coke oven riser waste heat recovery system still has the following major problems: the heat source of the system comes from the raw gas of the coke oven, and the coke oven is composed of several carbonization chambers, each of which operates periodically, that is, normally every 20-28 hours is an operation cycle. In one operation cycle, the carbonization chamber undergoes coal loading → carbonization and coking → coke maturation → coke pushing out. In these processes, raw gas is only produced during the carbonization and coking period (that is, the system can obtain heat source), and then provided to the riser heat exchanger of the recovery system for heat exchange, that is, the heat source of the recovery system is periodic and not always stable, which leads to periodic fluctuations in the temperature of the superheated steam generated (under the premise of unchanged steam flow), which does not meet the use requirements of the crude benzene distillation section. In addition, when the coke oven is reduced in production, due to the reduction in the amount of raw gas per unit time provided to the superheater system and the reduction in heat, the superheated steam temperature fluctuates, and its average temperature also decreases with the reduction in coke oven production (under the premise of unchanged steam flow). Utility Model Content

[0004] In order to achieve these purposes and other advantages according to the utility model, a preferred embodiment of the utility model provides a coke oven riser waste heat recovery system with controllable superheated steam temperature, comprising:

[0005] Desalted water tank, desalted water pump, deaerator, drum feed water pump, drum, forced circulation pump, riser evaporator, riser superheater, superheated steam flow regulating valve, water spray desuperheater and desuperheating water regulating valve;

[0006] Among them, the water outlet end of the desalted water tank is connected to the water inlet end of the desalted water pump, the water outlet end of the desalted water pump is connected to the water inlet end of the deaerator, the water outlet end of the deaerator is connected to the water inlet end of the drum feed water pump, the water outlet end of the drum feed water pump is simultaneously connected to the water inlets of two parallel-arranged drums, the steam outlet ends of the two drums are both connected to the steam inlet end of the riser superheater, the steam outlet end of the riser superheater is connected to the steam inlet end of the water spray desuperheater, the steam outlet end of the water spray desuperheater is connected to the user end, and the riser superheater is divided into two groups, which are arranged in parallel.

[0007] Preferably, the steam outlet end of the water spray desuperheater is connected to the user end, which is then connected in sequence to a superheated steam flow meter and a superheated steam temperature meter, and then to the user end.

[0008] Preferably, the water inlet end of the water spray desuperheater is connected to the circulating water pipeline of the forced circulation pump outlet, and the circulating water is used as the cooling water source of the water spray desuperheater.

[0009] Preferably, the riser superheaters are divided into two groups, with each group accounting for half of the total number, and the two groups are arranged at both ends of the same coke oven.

[0010] Preferably, the riser superheater is a dual-purpose evaporation and superheating type.

[0011] The utility model at least includes the following beneficial effects: the coke oven riser waste heat recovery system of the utility model can keep the total heat exchange amount of the superheater system unchanged, thereby ensuring that the superheated steam temperature remains stable.

[0012] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the coke oven riser waste heat recovery system with controllable superheated steam temperature in the utility model. DETAILED DESCRIPTION

[0014] The present invention will be further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0015] The following description is used to disclose the utility model so that those skilled in the art can implement the utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the utility model defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the utility model.

[0016] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0017] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0018] like Figure 1 As shown, one embodiment of the utility model provides a coke oven riser waste heat recovery system with controllable superheated steam temperature, comprising:

[0019] Desalted water tank 1, desalted water pump 2, deaerator 3, drum feed water pump 4, drum 5, forced circulation pump 6, riser evaporator 7, riser superheater 8, superheated steam flow regulating valve 9, water spray desuperheater 13, desuperheating water regulating valve 12;

[0020] Among them, the desalted water enters the desalted water tank 1 from the water inlet end of the desalted water tank 1, the water outlet end of the desalted water tank 1 is connected to the water inlet end of the desalted water pump 2, the water outlet end of the desalted water pump 2 is connected to the water inlet end of the deaerator 3, the water outlet end of the deaerator 3 is connected to the water inlet end of the drum feed water pump 4, the water outlet end of the drum feed water pump 4 is simultaneously connected to the water inlet ends of two drums 5 arranged in parallel, and the steam outlet ends of the two drums 5 are connected in parallel to the user end and the steam inlet end of the riser superheater 8. The steam outlet end of the riser superheater 8 is connected to the steam inlet end of the spray water desuperheater 13, and the steam outlet end of the spray water desuperheater 13 is connected to the user end, and the riser superheater 8 is divided into two groups, which are arranged in parallel. There are two desalted water pumps 2, which are arranged in parallel. There are two drum feed water pumps 4, which are arranged in parallel.

[0021] Desalted water is pressurized by desalted water pump 2 from desalted water tank 1 and sent to deaerator 3 for deoxygenation. The desalted water (referred to as deoxygenated water) is pressurized by drum feed water pump 4 and sent to drum 5. The water in the drum is pressurized by forced circulation pump 6 and sent to riser evaporator 7 for heat exchange with raw coal gas supplied from coke oven. The steam-water mixture after heat exchange returns to drum 5 for steam-water separation. Part of the separated saturated steam is directly supplied to users, and the other part is sent to riser superheater 8 through superheated steam flow regulating valve 9 for heat exchange with raw coal gas supplied from coke oven. After heat exchange, the saturated steam becomes superheated steam. The superheated steam enters water spray desuperheater 13 and is mixed with circulating water connected from the outlet of forced circulation pump 6 for temperature adjustment.

[0022] In the existing system, the temperature of superheated steam fluctuates with the periodic production rhythm of each carbonization chamber of the coke oven while keeping the steam flow unchanged, and the general fluctuation range is 50-100℃. This patent first divides the riser superheater into two groups and arranges them separately to avoid all superheaters reaching the end of a cycle in a similar time period as much as possible, that is, to avoid the simultaneous heat exchange or no heat exchange of each superheater. Secondly, since the heat absorbed by water vaporization into steam is very large (i.e., the latent heat of vaporization, about 2000kJ / kg), and the heat capacity of steam is very small, the excessive steam temperature can be lowered by adding a small amount of water to the superheated steam. When there is water spray cooling, the amount of steam entering the superheater is reduced by the superheated steam flow regulating valve, so that the total mass of steam and water remains unchanged. Under the condition of stabilizing the steam flow, the heat absorption of steam in the superheater can also be reduced. In summary, the superheated steam temperature is controlled while keeping the superheated steam flow unchanged.

[0023] In the above implementation scheme, the riser evaporator and the riser superheater are collectively referred to as riser heat exchangers, which are located at the top of one end of each carbonization chamber of the coke oven. The raw gas flow generated by each carbonization chamber passes through its own riser heat exchanger and enters the gas collecting pipe and subsequent purification process.

[0024] The desalted water tank 1, desalted water pump 2, and deaerator 3 in the recovery system are auxiliary equipment, and their function is to provide qualified water quality (heating medium for the riser evaporator) for the circulation heating system. The steam drum 5, the forced circulation pump 6, the riser evaporator 7, and the unillustrated connecting pipes are the circulation heating system for heating water into saturated steam, and the riser superheater 8, the superheated steam flow regulating valve 9, and the unillustrated connecting pipes are the superheater system for heating saturated steam into superheated steam.

[0025] The water spray desuperheater 13 is used to adjust the superheated steam temperature. A small amount of circulating water (0-5% of the superheated steam amount) is introduced from the circulating heating system and mixed with the superheated steam in the water spray desuperheater 13. The circulating water is heated and vaporized by the superheated steam to become superheated steam, and the original superheated steam is cooled due to heat release.

[0026] The riser superheater 8 is a dual-purpose evaporation and superheating type, that is, it can be used as a riser evaporator to generate saturated steam, and can also be used as a riser superheater to generate superheated steam. Its number is kept at a certain surplus. When the coke oven is reduced in production, a larger number of superheaters can be switched to keep the total heat exchange of the superheater system unchanged, thereby ensuring that the temperature of the superheated steam remains stable.

[0027] In this scheme, the riser superheaters 8 are divided into two groups and arranged at both ends of a coke oven (50% each), so that the operation cycles of the carbonization chambers corresponding to the superheaters are staggered as much as possible, thereby reducing the fluctuation range of the steam temperature;

[0028] The cooling water for the spray water desuperheater 13 is taken from the circulating water system. Compared with the spray water desuperheater of the boiler which usually takes the cooling water from the drum feed water, the cooling water pipeline length is greatly shortened, and the pressure and water volume are stable.

[0029] In another technical solution, the water outlet end of the water spray desuperheater 13 is connected to the user end, which is then connected to the superheated steam flow meter 10 and the superheated steam temperature meter 11 in sequence, and then connected to the user end.

[0030] In another technical solution, the water outlet of the steam drum 5 is connected to the water inlet of the riser superheater 8 through a superheated steam flow regulating valve 9 .

[0031] The water outlets of the two steam drums 5 are also connected in sequence to the forced circulation pump 6, the desuperheating water regulating valve 12, and the riser evaporator 7. The water outlet of the desuperheating water regulating valve 12 is connected to the water inlet of the spray water desuperheater 13. The opening of the sequence number 12 is controlled by the measured value of 11, the amount of the introduced circulating water is adjusted, and then the superheated steam temperature is adjusted; the riser evaporator 7 is a plurality of risers, which are arranged in parallel.

[0032] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A coke oven riser waste heat recovery system with controllable superheated steam temperature, characterized in that: include: Desalted water tank, desalted water pump, deaerator, drum feed water pump, drum, forced circulation pump, riser evaporator, riser superheater, superheated steam flow regulating valve, water spray desuperheater and desuperheating water regulating valve; Among them, the water outlet end of the desalted water tank is connected to the water inlet end of the desalted water pump, the water outlet end of the desalted water pump is connected to the water inlet end of the deaerator, the water outlet end of the deaerator is connected to the water inlet end of the drum feed water pump, the water outlet end of the drum feed water pump is simultaneously connected to the water inlets of two parallel-arranged drums, the steam outlet ends of the two drums are both connected to the steam inlet end of the riser superheater, the steam outlet end of the riser superheater is connected to the steam inlet end of the water spray desuperheater, the steam outlet end of the water spray desuperheater is connected to the user end, and the riser superheater is divided into two groups, which are arranged in parallel.

2. The coke oven riser waste heat recovery system with controllable superheated steam temperature according to claim 1, characterized in that: The steam outlet end of the water spray desuperheater is connected to the user end, which is then connected to a superheated steam flow meter and a superheated steam temperature meter in sequence, and then connected to the user end.

3. The coke oven riser waste heat recovery system with controllable superheated steam temperature according to claim 1, characterized in that: The water inlet end of the water spray desuperheater is connected to the circulating water pipeline of the forced circulation pump outlet, and the circulating water is used as the cooling water source of the water spray desuperheater.

4. The coke oven riser waste heat recovery system with controllable superheated steam temperature according to claim 1, characterized in that: The riser superheaters are divided into two groups, each group accounts for half of the total number, and the two groups are arranged at both ends of the same coke oven.

5. The coke oven riser waste heat recovery system with controllable superheated steam temperature according to claim 1, characterized in that: The riser superheater is a dual-purpose evaporation and superheating type.

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