CN115854707A

CN115854707A - Rotary kiln steam quality upgrading system and method

Info

Publication number: CN115854707A
Application number: CN202211604707.4A
Authority: CN
Inventors: 冯建新
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-12-13
Filing date: 2022-12-13
Publication date: 2023-03-28

Abstract

The embodiment of the application provides a rotary kiln Steam Quality Upgrading System (SQUS) and a method, including the rotary kiln that communicates in proper order, the kiln hood cover, the grate cooler, kiln hood cover boiler (YTG) is connected with at kiln hood cover top, set up one-level over heater and second grade over heater in the kiln hood cover boiler, rotary kiln externally mounted barrel evaporimeter, the steam-water mixture that kiln hood cover boiler water-cooling wall and barrel evaporimeter (TZ) produced gets into the steam pocket and mixes and steam-water separation, steam mixes with the steam that comes from AQC and SP exhaust-heat boiler behind the one-level over heater, carry and carry out steam quality upgrading in the second grade over heater, rotary kiln system high temperature radiation used heat reuse technology bottleneck can be solved, AQC and SP exhaust-heat boiler originally can only carry out pure low temperature waste heat power generation, obtain medium temperature low pressure high quality steam after the second grade is overheated, power generation efficiency is improved, ton product and production system's generated energy, be applicable to the comprehensive waste heat utilization field of rotary kiln system.

Description

Rotary kiln steam quality upgrading system and method

Technical Field

The application relates to the field of comprehensive utilization of waste heat of a rotary kiln system, in particular to a rotary kiln steam quality upgrading system and a rotary kiln steam quality upgrading method.

Background

The heat of hot air pumped out from an air suction port of a kiln head grate cooler of a production line in the prior art and smoke exhausted by a primary preheater are utilized to change the heat of vapor into the heat of the vapor through an AQC waste heat boiler and an SP waste heat boiler to carry out pure low-temperature waste heat power generation.

On the other hand, when the rotary kiln barrel and the kiln head cover work, the shell can discharge a large amount of high-temperature radiation waste heat, the high temperature of the radiation waste heat can not only cause great adverse effect on the working environment of workers, but also can shorten the service life of main thermotechnical equipment, and needs frequent use and replacement of expensive high-temperature resistant materials for isolation protection, thereby increasing extra cost; and because the high-temperature radiation waste heat can not be absorbed and utilized, the high-temperature heat carried by the high-temperature radiation waste heat is wasted wastefully, so that the heat efficiency of the whole thermal engineering system is reduced.

Disclosure of Invention

In order to break through the technical bottleneck, the embodiment of the application provides a system and a method for upgrading the steam quality of the rotary kiln.

According to the first aspect of this application embodiment provides a rotary kiln steam quality system of upgrading again, including the rotary kiln that communicates in proper order, kiln hood cover and grate cooler, kiln hood cover top is connected with kiln hood cover boiler, be equipped with the water-cooling wall on the kiln hood cover boiler shell, the output of water-cooling wall is connected with the steam pocket, a plurality of barrel evaporimeters are installed along the axial to the rotary kiln barrel outside, the output and the steam pocket of barrel evaporimeter are connected, install one-level over heater and second grade over heater in the kiln hood cover boiler, the play steam end of steam pocket links to each other with the input of one-level over heater, the output of one-level over heater is connected with the collection steam chest, the output of collection steam chest links to each other with the input of second grade over heater, the output of second grade over heater is connected with the steam turbine.

Furthermore, the steam generator also comprises an AQC waste heat boiler and an SP waste heat boiler, wherein the steam output ends of the AQC waste heat boiler and the SP waste heat boiler are respectively connected with the input end of the steam collection box.

Furthermore, a water pump is connected to a water inlet of the steam drum, two water outlets of the steam drum are respectively connected with the input ends of the water-cooled wall and the cylinder evaporator through a down pipe and a down pipe group, and two input ends of the steam drum are respectively connected with the output ends of the water-cooled wall and the cylinder evaporator through an up pipe and an up pipe group.

Further, still include air cooling system, air cooling system locates the outside barrel evaporimeter of rotary kiln and the outside insulating layer of barrel evaporimeter is located to the cover including the cover, and air outlet and the income wind gap that runs through barrel evaporimeter and insulating layer are seted up respectively to air cooling system bottom and top, and the income wind gap department is equipped with the fan.

Further, the barrel evaporimeter includes that the cover locates the evaporimeter nest of tubes on the rotary kiln after two locks, and the insulating layer includes that the cover locates the thermal-insulated module on the barrel evaporimeter after two locks, and the barrel evaporimeter nest of tubes and the thermal-insulated module that lie in with one side pass through the connecting piece and link to each other.

Furthermore, a temperature detection device is arranged at an outlet of the secondary superheater, and a desuperheater is arranged in the steam collection box corresponding to the temperature detection device.

According to a second aspect of the embodiments of the present application, there is provided a rotary kiln steam quality upgrading method, including the following steps:

s10, preheating: the water pump supplies the treated low-temperature deoxygenated water to a steam pocket, the steam pocket conveys the low-temperature deoxygenated water to a water-cooled wall and a barrel evaporator through a downcomer and a downcomer pipe group respectively, and high-temperature radiation waste heat in a kiln head cover and a rotary kiln barrel heats the low-temperature deoxygenated water in the water-cooled wall and the barrel evaporator respectively to form a steam-water mixture with the temperature of 170-175 ℃;

s20, steam-water separation: steam-water mixtures from the water-cooled wall and the barrel evaporator are respectively conveyed into a steam drum through an ascending pipe and an ascending pipe group to be mixed, then steam-water separation is carried out, low-temperature low-pressure steam and water at 170-175 ℃ are respectively obtained, the water at 170-175 ℃ is mixed with deoxygenated water supplemented by a water pump into low-temperature water, and the low-temperature water is respectively returned into the water-cooled wall and the barrel evaporator through a descending pipe and a descending pipe group to be circulated;

s30, primary overheating: low-temperature low-pressure steam is conveyed into a primary superheater through a pipeline, and the low-temperature low-pressure steam absorbs radiation waste heat in a kiln hood through the primary superheater to obtain superheated steam with the temperature of 300 ℃ of 330-DEG C;

s40, secondary overheating: the superheated steam passes through the steam collection box and is then conveyed into the secondary superheater, the superheated steam continuously absorbs the radiation waste heat in the kiln hood through the secondary superheater, and medium-temperature medium-pressure steam at the temperature of 430 ℃ and 1.5Kpa or medium-temperature low-pressure steam at the temperature of 430 ℃ and 1.2Kpa is obtained;

s50, power generation: and (3) conveying the medium-temperature medium-pressure or medium-temperature low-pressure steam to a steam turbine to drive the steam turbine and drive a generator to generate power.

Further, the step S40 of secondary superheating further comprises:

s401, upgrading the steam quality again: conveying steam at 300-330 ℃ generated by an AQC waste heat boiler and steam at 285-300 ℃ generated by an SP waste heat boiler to a steam collection box, mixing the AQC steam, the SP steam and the superheated steam in the steam collection box to form mixed superheated steam, conveying the mixed superheated steam to a secondary superheater, and continuously absorbing the radiation waste heat in a kiln hood by the mixed superheated steam through the secondary superheater to obtain medium-temperature medium-pressure steam at 430 ℃ and 1.5Kpa or medium-temperature medium-pressure steam at 430 ℃ and 1.2 Kpa.

Further, S10, the preheating step further includes:

s101, convective heat transfer: and opening the fan to enable outside cold air to enter the air cooling system through the air inlet, cooling a local overheating area at the bottom of the rotary kiln, continuously collecting and discharging heated air to the air outlet along a gap between the rotary kiln and the barrel evaporator and a gap between the barrel evaporator and the heat insulation layer respectively, and transferring heat between the rotary kiln shell and the barrel evaporator by the heated air to form convection heat transfer.

Furthermore, the temperature detection device is responsible for monitoring the outlet steam temperature of the secondary superheater in real time, and when the steam temperature exceeds the set rated temperature of the steam turbine, the desuperheater is automatically started to cool the mixed superheated steam in the steam collection box; and when the steam temperature is lower than the set rated temperature of the steam turbine, the desuperheater is automatically closed.

By adopting the rotary kiln steam quality upgrading system and method provided by the embodiment of the application, a plurality of barrel evaporators are sleeved outside the rotary kiln to recover the radiation waste heat generated by the rotary kiln shell, so that a preheated steam-water mixture is obtained; a kiln hood boiler is arranged above the kiln hood cover, a primary superheater and a secondary superheater are arranged above the interior of the kiln hood boiler, and the radiation waste heat in the kiln hood cover is recovered; the steam generated by the AQC waste heat boiler and the SP waste heat boiler is mixed with the preheated steam after primary overheating, the mixed superheated steam is subjected to secondary overheating to obtain medium-temperature low-pressure high-quality steam for power generation, the technical bottleneck that the high-temperature radiation waste heat of the rotary kiln and the kiln hood shell is difficult to utilize is overcome, the medium-temperature low-pressure high-quality steam can be obtained after mixing and secondary overheating of the AQC waste heat boiler and the SP waste heat boiler which can only be used for pure low-temperature waste heat power generation originally, and the power generation efficiency, the ton product generated energy and the thermal efficiency of a production system are greatly improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic structural diagram of a rotary kiln steam quality upgrading system according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of an air cooling system according to an embodiment of the present disclosure;

FIG. 3 is a schematic structural view of a tube bank and a heat insulation module of a barrel evaporator according to an embodiment of the present disclosure;

the system comprises a rotary kiln 10, a kiln head cover 20, a grate cooler 30, a kiln head cover boiler 40, a water-cooled wall 401, a primary superheater 402, a secondary superheater 403, a downcomer 404, an ascending pipe 405, a temperature detection device 406, a steam pocket 50, a water pump 501, a barrel evaporator 60, a descending pipe group 601, an ascending pipe group 602, an evaporator pipe group 603, a steam collection box 70, a desuperheater 701, a steam turbine 80, an air cooling system 90, a heat insulation layer 901, an air outlet 902, an air inlet 903, a fan 904, a heat insulation module 905 and a connecting support 906.

Detailed Description

In order to make the technical solutions and advantages in the embodiments of the present application more clearly understood, the following description of the exemplary embodiments of the present application with reference to fig. 1 to 3 is made in further detail, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and are not exhaustive of all the embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

In the process of realizing the application, the inventor finds that the existing novel dry-method cement clinker production line utilizes hot air pumped out from the air suction port of the kiln head grate cooler of the existing production line and the heat of smoke exhausted by the primary preheater, the heat enthalpy of the water vapor is changed into through the AQC waste heat boiler and the SP waste heat boiler to carry out pure low-temperature waste heat power generation, because the method can only obtain low-temperature low-pressure steam, most heat enthalpies of a power generation system are insufficient, the main steam pressure is low, the designed rated power generation capacity can not be reached, and the power generation efficiency and the ton product power generation capacity are low.

On the other hand, when the rotary kiln and the kiln head cover work, the shell can discharge a large amount of high-temperature radiation waste heat, the high temperature of the radiation waste heat can not only cause great adverse effect on the working environment of workers, but also can shorten the service life of main thermotechnical equipment, and needs frequent use and replacement of expensive high-temperature resistant materials for isolation protection, thereby increasing extra cost; and because the high-temperature radiant heat can not be absorbed and utilized, the high-temperature heat carried by the high-temperature radiant heat is wasted wastefully, so that the heat efficiency of a thermal system of a process production line is reduced.

In view of the above problems, a first aspect of the embodiments of the present application provides a rotary kiln Steam quality upgrading system (SQUS, in fact, a rotary kiln Steam quality upgrading system in the present invention may also be referred to as a rotary kiln Steam multi-stage centralized overheating system), which includes a rotary kiln 10, a kiln head cover 20 and a grate cooler 30 that are sequentially connected, and a kiln head cover boiler 40 (code YTG, pronunciation: yite pavilion), the bottom of the kiln hood boiler 40 is higher than the rotary kiln mouth and the height of the tertiary air pipe, the kiln hood boiler 40 is communicated with the kiln hood 30, and no air outlet is arranged in the kiln hood boiler, the design is adopted to avoid the influence of the kiln hood boiler 40 on the tertiary air and the secondary air of the production process system, namely, the tertiary air, the secondary air and other hot air of the production process system cannot flow into the kiln hood boiler 40, the kiln hood boiler 40 absorbs radiation waste heat in the kiln hood 20 by using the black hole principle, a water-cooled wall 401 is arranged on the shell of the kiln hood boiler 40, the output end of the water-cooled wall 401 is connected with a Steam pocket 50, a plurality of barrel evaporators 60 (code TZ and pronunciation: tez) are axially arranged outside the barrel of the rotary kiln 10, the barrel evaporators 60 are arranged at the position of the rotary kiln 10 with higher temperature (not less than 200 ℃), the output ends of the barrel evaporators 60 are connected with a Steam pocket 50, a primary superheater 402 and a secondary superheater are arranged in the kiln hood boiler 40, the Steam outlet end of the Steam pocket 50 is connected with the input end of the Steam pocket 402, the secondary superheater is connected with the output end of the Steam pocket 403 of the Steam pocket 70, the output end of the secondary superheater 403 is connected with a steam turbine 80.

Specifically, the barrel evaporator 50 absorbs the radiant waste heat emitted by the barrel of the rotary kiln 10, the water wall 401 on the kiln head cover boiler 40 absorbs the radiant waste heat in the kiln head cover 30, the two obtain steam-water mixtures respectively, then the steam-water mixtures are sent to the steam drum 50 to be mixed and subjected to steam-water separation, the steam obtained after separation is subjected to secondary superheating by the primary superheater 402 and the secondary superheater 403 to obtain medium-temperature medium-pressure steam or medium-temperature low-pressure steam, and the medium-temperature medium-pressure steam or the medium-temperature low-pressure steam is sent to the steam turbine 80 to be used for power generation.

Further, still include AQC exhaust-heat boiler and SP exhaust-heat boiler, the steam output of AQC exhaust-heat boiler and SP exhaust-heat boiler is equallyd divide and is connected with the input of collection steam box 70 respectively.

Specifically, the steam-water mixture obtained from the barrel evaporator 50 and the water wall 401 is subjected to mixing and steam-water separation by the steam drum 50, the steam temperature obtained after the superheated steam passes through the primary superheater 402 is similar to the steam temperature generated by the AQC waste heat boiler and the SP preheating boiler, the steam-water mixture, the AQC waste heat boiler, the SP preheating boiler, the AQC waste heat boiler, the SP waste heat boiler, the AQC waste heat boiler and the SP preheating boiler are mixed by the steam collection box 70, the mixture enters the secondary superheater 403 for secondary superheating, the steam quality is upgraded, and the obtained medium-temperature medium-pressure steam or medium-temperature low-pressure steam is sent to the steam turbine 80 for power generation.

Further, a water pump 501 is connected to a water inlet of the steam drum 50, the water pump 501 is connected to demineralized deoxygenated water, two water outlets of the steam drum 50 are respectively connected to the water-cooled wall 401 and the input end of the drum evaporator 60 through a down pipe 404 and a down pipe group 601, and two input ends of the steam drum 50 are respectively connected to the water-cooled wall 401 and the output end of the drum evaporator 60 through an up pipe 405 and an up pipe group 602.

The steam pocket 50 can not only separate steam from water, but also provide a heat exchange medium for the water wall 401 and the barrel evaporator 60 for circulation; the softened deoxygenated water is heated to 106 ℃ by a low-temperature economizer and then is heated to 150-170 ℃ by a high-temperature economizer to be used as the supplementary water of the steam pocket 50.

Further, the air cooling system 90 is further included, the air cooling system 90 includes a barrel evaporator 60 sleeved outside the rotary kiln 10 and a heat insulation layer 901 sleeved outside the barrel evaporator 60, an air outlet 902 and an air inlet 903 penetrating through the barrel evaporator 60 and the heat insulation layer 901 are respectively formed in the bottom and the top of the air cooling system 90, and a fan 904 is arranged at the air inlet 903.

Specifically, when the thermal equipment is operating normally, the drum evaporator 60 absorbs the radiant waste heat from the high temperature section of the drum of the rotary kiln 10; on the other hand, the fan 904 inputs external cold air into the air cooling system 90 through the air inlet 903, and the external cold air passes through the rotary kiln 10 barrel to cool the local overheating area at the bottom of the rotary kiln 10 barrel generated in the production process, and the heated air continues to collect and discharge to the air outlet 902 along the gap between the rotary kiln 10 barrel and the barrel evaporator 60 and the gap between the barrel evaporator 60 and the heat insulation layer 901, so that in the process, the heated air transfers heat between the rotary kiln 10 barrel and the barrel evaporator 60 to form convection heat transfer, and the temperature of each area of the rotary kiln 10 barrel gradually tends to be stable while the fan 203 takes away heat loss, so that each area of the barrel evaporator 60 is heated uniformly, the heat exchange medium in the barrel evaporator 60 is guaranteed to be heated uniformly and sufficiently, and the yield of the steam-water mixture of the barrel evaporator 60 is improved.

Further, the barrel evaporator 60 includes two evaporator tube groups 603 sleeved on the rotary kiln 10 after being fastened, the heat insulation layer 901 includes two heat insulation modules 905 sleeved on the barrel evaporator 60 after being fastened, and the barrel evaporator tube groups 603 and the heat insulation modules 905 located on the same side are connected through a connecting member.

Specifically, the evaporator tube group 603 and the heat insulation module 905 which are positioned on the same side are integrally arranged, the heat insulation module 905 is externally connected with an air cooling system 90 shell, the air cooling system 90 shell and the heat insulation module 905 are arranged at intervals and connected through a connecting piece, openings are arranged at positions of the air cooling system 90 shell corresponding to the air outlet 902 and the air inlet 903, a connecting support 906 arranged on the ground is adopted to fix an integrated structure which is positioned on the same side and consists of the evaporator tube group 603, the heat insulation module 905 and the air cooling system 90 shell, and the integrated structure positioned on two sides of the rotary kiln 10 is connected through the connecting piece and then sleeved on the rotary kiln 10 to complete the assembly of the air cooling system 90;

adopt the integral type structure to divide air cooling system 90 into about two modules, on the one hand because will reserve air outlet 902 and the income wind gap 903 that is located air cooling system 90 top and bottom, on the other hand, such design can bring convenient to detach, reduce cost of maintenance's benefit, if certain evaporimeter nest of tubes 603 takes place to damage needs to be changed, only need to remove about two integral type structures connect the back and dismantle the integral type structure of this side from linking bridge 906, and need not like traditional heat transfer device with whole device dismantlement change, a large amount of cost of maintenance have been saved.

Further, a temperature detection device 406 is disposed at an outlet of the secondary superheater 403, and a desuperheater 701 is disposed in the steam collection box 70 corresponding to the temperature detection device.

The temperature detection device 406 is used for monitoring the steam temperature at the outlet of the secondary evaporator 403 in real time, the desuperheater 701 is used for cooling the mixed superheated steam in the steam collection box 70 after receiving a cooling instruction, the temperature detection device 406 and the desuperheater 701 jointly form an automatic control system, the steam temperature at the outlet of the secondary evaporator 403 is kept within a set rated temperature range of the steam turbine 80 when the steam quality is upgraded, and the steam quality is maximized within the rated working temperature of the steam turbine 80.

s10, preheating: the water pump 601 supplies the treated low-temperature deoxygenated water to the steam drum 50, the steam drum 50 then respectively conveys the low-temperature deoxygenated water to the water-cooled wall 401 and the barrel evaporator 60 through the down pipes 404 and the down pipe group 601, and the high-temperature radiation waste heat of the kiln head cover 20 and the rotary kiln 10 respectively heats the low-temperature deoxygenated water in the water-cooled wall 401 and the barrel evaporator 60 to form a steam-water mixture with the temperature of 170-175 ℃;

s20, steam-water separation: the steam-water mixture from the water-cooled wall 401 and the barrel evaporator 60 is respectively conveyed into the steam drum 50 through the ascending pipe 405 and the ascending pipe group 602 to be mixed and then subjected to steam-water separation, so that low-temperature low-pressure steam and water at 170-175 ℃ are respectively obtained, the water at 170-175 ℃ is mixed with deoxygenated water supplemented by the water pump 501 to form low-temperature water, and the low-temperature water is respectively returned into the water-cooled wall 401 and the barrel evaporator 60 through the descending pipe 404 and the descending pipe group 601 to be circulated;

s30, primary overheating: low-temperature low-pressure steam is conveyed into the primary superheater 402 through a pipeline, and the low-temperature low-pressure steam absorbs the radiation waste heat in the kiln head cover 30 through the primary superheater 402 to obtain superheated steam at the temperature of 300 ℃ to 330 ℃ -DEG C;

s40, secondary overheating: the superheated steam passes through the steam collection box 70 and then is conveyed into the secondary superheater 403, the superheated steam continuously absorbs the radiation waste heat in the kiln head cover 30 through the secondary superheater 403, and medium-temperature medium-pressure steam at 430 ℃ and 1.5Kpa or medium-temperature low-pressure steam at 430 ℃ and 1.2Kpa is obtained;

s50, power generation: the medium-temperature medium-pressure or medium-temperature low-pressure steam is delivered to the steam turbine 80, drives the steam turbine 80 and drives the generator to generate electricity.

Further, the step S40 of secondary superheating further comprises:

s401, upgrading the steam quality again: the steam with the temperature of 300-330 ℃ generated by the AQC waste heat boiler and the steam with the temperature of 285-300 ℃ generated by the SP waste heat boiler are delivered to a steam collection box 80, the AQC steam, the SP steam and the superheated steam are mixed in the steam collection box 80 to form mixed superheated steam, the mixed superheated steam is delivered to a secondary superheater 403, and the mixed superheated steam continuously absorbs the radiation waste heat in the kiln head cover 30, the medium-temperature medium-pressure steam with the temperature of 430 ℃ and 1.5Kpa or the medium-temperature medium-pressure steam with the temperature of 430 ℃ and 1.2Kpa through the secondary superheater 403.

Further, S10, the preheating step further includes:

s101, convective heat transfer: the fan 904 is turned on, so that the outside cold air enters the air cooling system 90 through the air inlet 903, the local superheated area at the bottom of the rotary kiln 10 is cooled, the heated air is collected and discharged to the air outlet 902 respectively along the gap between the rotary kiln 10 and the barrel evaporator 60 and the gap between the barrel evaporator 60 and the heat insulation layer 901, and the heated air transfers heat between the shell of the rotary kiln 10 and the barrel evaporator 60, so as to form convection heat transfer.

Further, the temperature detection device 406 is responsible for monitoring the outlet steam temperature of the secondary superheater 403 in real time, and when the steam temperature exceeds the set rated temperature of the steam turbine 80, the desuperheater 701 is automatically started to cool the mixed superheated steam in the steam header 70; the desuperheater automatically shuts off when the steam temperature is below the set rated temperature of the steam turbine 80. Specifically, when the steam temperature exceeds 430 ℃, the desuperheater 701 is automatically started to cool the mixed superheated steam in the steam collection box 70, and when the steam temperature is lower than 400 ℃, the desuperheater is automatically closed to keep the mixed superheated steam within the range of 400-430 ℃.

By adopting the system and the method for upgrading the Steam quality of the rotary kiln, a plurality of barrel evaporators (code number TZ) are sleeved outside the rotary kiln to recover the radiation waste heat generated by the rotary kiln barrel, a kiln head cover boiler (code number YTG) water-cooled wall is arranged above a kiln head cover to absorb the radiation waste heat in the kiln head cover, and the Steam-water mixture is obtained and subjected to Steam-water separation after being mixed by a Steam pocket; the steam after steam-water separation is superheated through a primary superheater to obtain superheated steam; a primary superheater and a secondary superheater are arranged above the interior of the kiln hood boiler, and the radiant waste heat in the kiln hood is continuously recovered; steam generated by the AQC waste heat boiler and the SP waste heat boiler is mixed with superheated steam after primary superheating, the mixed superheated steam is subjected to steam quality upgrading through the secondary superheater, high-quality steam of medium-temperature medium-pressure or medium-temperature low-pressure steam is obtained for power generation, the technical bottleneck that high-temperature radiation waste heat of a rotary kiln and a kiln hood shell is difficult to utilize is overcome, the AQC waste heat boiler and the SP waste heat boiler which originally can only perform pure low-temperature waste heat power generation can be mixed and subjected to secondary superheating to obtain medium-temperature medium-pressure or medium-temperature low-pressure high-quality steam, and the power generation efficiency, ton product power generation capacity and the thermal efficiency of a production system are greatly improved. And has strong practicability.

In the description of the present application, it is to be understood that the terms "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings, which are based on the orientations and positional relationships indicated in the drawings, and are used for convenience in describing the present application and for simplicity in description, but do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present application.

In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically connected, electrically connected or can communicate with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as the case may be.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. The utility model provides a rotary kiln steam quality upgrades system again, its characterized in that, including rotary kiln (10), kiln hood cover (20) and the cold machine of comb (30) that communicate in proper order, kiln hood cover (20) top is connected with kiln hood cover boiler (40), be equipped with water-cooling wall (401) on kiln hood cover boiler (40) casing, the output of water-cooling wall (401) is connected with steam pocket (50), a plurality of barrel evaporimeters (60) are installed along the axial to rotary kiln (10) barrel outside, the output of barrel evaporimeter (60) with steam pocket (50) are connected, install one-level superheater (402) and second grade superheater (403) in kiln hood boiler (40), the play steam end of steam pocket (50) with the input of one-level superheater (402) links to each other, the output of one-level superheater (402) is connected with collection steam chest (70), the output of collection steam chest (70) with the input of second grade superheater (403) links to each other, the output of second grade superheater (403) is connected with steam turbine (80).

2. The rotary kiln steam quality upgrading system as claimed in claim 1, further comprising an AQC waste heat boiler and an SP waste heat boiler, wherein steam output ends of the AQC waste heat boiler and the SP waste heat boiler are respectively connected with an input end of the steam collection box (70).

3. The rotary kiln steam quality upgrading system according to claim 1, characterized in that a water pump (501) is connected to a water inlet of the steam drum (50), two water outlets of the steam drum (50) are respectively connected to the water wall (401) and the input end of the drum evaporator (60) through a down pipe (404) and a down pipe group (601), and two input ends of the steam drum (50) are respectively connected to the water wall (401) and the output end of the drum evaporator (60) through an up pipe (405) and an up pipe group (602).

4. The rotary kiln steam quality upgrading system as claimed in claim 1, further comprising an air cooling system (90), wherein the air cooling system (90) comprises a barrel evaporator (60) sleeved outside the rotary kiln (10) and a heat insulation layer (901) sleeved outside the barrel evaporator (60), an air outlet (902) and an air inlet (903) penetrating through the barrel evaporator (60) and the heat insulation layer (901) are respectively formed in the bottom and the top of the air cooling system (90), and a fan (904) is arranged at the air inlet (903).

5. The rotary kiln steam quality upgrading system as claimed in claim 4, wherein the barrel evaporator (60) comprises two evaporator tube sets (603) which are fastened and then sleeved on the rotary kiln (10), the heat insulation layer (901) comprises two heat insulation modules (905) which are fastened and then sleeved on the barrel evaporator (60), and the barrel evaporator tube sets (603) and the heat insulation modules (905) which are located on the same side are connected through connecting pieces.

6. The rotary kiln steam quality upgrading system as claimed in claim 1, wherein a temperature detection device (406) is arranged at an outlet of the secondary superheater (403), and a desuperheater (701) is arranged in the steam collection box (70) corresponding to the temperature detection device.

7. A rotary kiln steam quality re-upgrading method comprising a rotary kiln steam quality re-upgrading system as claimed in any one of claims 1 to 6, characterized by comprising the steps of:

s10, preheating: the water pump (601) supplies the treated low-temperature deoxygenated water to the steam drum (50), the steam drum (50) respectively conveys the low-temperature deoxygenated water to the water-cooled wall (401) and the cylinder evaporator (60) through the down pipes (404) and the down pipe group (601), and the high-temperature radiation waste heat of the kiln head cover (20) and the rotary kiln (10) respectively heats the low-temperature deoxygenated water in the water-cooled wall (401) and the cylinder evaporator (60) to form a steam-water mixture with the temperature of 170-175 ℃;

s20, steam-water separation: steam-water mixtures from the water-cooled wall (401) and the barrel evaporator (60) are respectively conveyed into a steam drum (50) through an ascending pipe (405) and an ascending pipe group (602) to be mixed and then subjected to steam-water separation, so that low-temperature low-pressure steam and water at 170-175 ℃ are respectively obtained, the water at 170-175 ℃ is mixed with deoxygenated water supplemented by a water pump (501) to form low-temperature water, and the low-temperature water is respectively returned into the water-cooled wall (401) and the barrel evaporator (60) through a descending pipe (404) and a descending pipe group (601) to be circulated;

s30, primary overheating: low-temperature low-pressure steam is conveyed into a primary superheater (402) through a pipeline, and the low-temperature low-pressure steam absorbs radiation waste heat in a kiln head cover (30) through the primary superheater (402) to obtain superheated steam at the temperature of 300 ℃ to 330-DEG C;

s40, secondary overheating: the superheated steam passes through the steam collection box (70) and then is conveyed into the secondary superheater (403), the superheated steam continuously absorbs the radiation waste heat in the kiln head cover (30) through the secondary superheater (403) to obtain middle-temperature middle-pressure steam at 430 ℃ and 1.5Kpa or middle-temperature low-pressure steam at 430 ℃ and 1.2 Kpa;

s50, power generation: and the medium-temperature medium-pressure or medium-temperature low-pressure steam is conveyed to a steam turbine (80), and the steam turbine (80) is driven to drive a generator to generate electricity.

8. The rotary kiln steam quality upgrading method as claimed in claim 7, wherein: the step S40 of secondary superheating further comprises the following steps:

s401, upgrading the steam quality again: the method comprises the steps of conveying 300-330 ℃ steam generated by an AQC waste heat boiler and 285-300 ℃ steam generated by an SP waste heat boiler to a steam collection box (80), mixing the AQC steam, the SP steam and the superheated steam in the steam collection box (80) to form mixed superheated steam, conveying the mixed superheated steam into a secondary superheater (403), and continuously absorbing radiation waste heat in a kiln head cover (30), medium-temperature medium-pressure steam of 430 ℃, 1.5Kpa or medium-temperature medium-pressure steam of 430 ℃ and 1.2Kpa by the mixed superheated steam through the secondary superheater (403).

9. The rotary kiln steam quality upgrading method as claimed in claim 7, wherein: s10, the preheating step further comprises:

s101, convective heat transfer: and opening a fan (904), enabling outside cold air to enter an air cooling system (90) through an air inlet (903), cooling a local overheating area at the bottom of the rotary kiln (10), continuously collecting and discharging heated air to an air outlet (902) along a gap between the rotary kiln (10) and the barrel evaporator (60) and a gap between the barrel evaporator (60) and the heat insulation layer (901), and transferring heat between the shell of the rotary kiln (10) and the barrel evaporator (60) by the heated air to form convection heat transfer.

10. The rotary kiln steam quality upgrading method as claimed in claim 6, wherein: the temperature detection device (406) is responsible for monitoring the outlet steam temperature of the secondary superheater (403) in real time, and when the steam temperature exceeds the set rated temperature of the steam turbine (80), the desuperheater (701) is automatically started to cool the mixed superheated steam in the steam collection box (70); the desuperheater automatically shuts down when the steam temperature is below a set rated temperature for the steam turbine (80).