CN214468540U - Sludge mixed combustion system utilizing condensate water of thermal power generating unit for pre-drying - Google Patents

Abstract

The utility model provides an utilize thermal power generating unit condensate water predrying's mud to mix system of burning, it has sludge dryer, and the part condensate water that draws forth from thermal power generating unit's backheating system is used for heating mud in order to carry out mud predrying, and the mud through predrying gets into the boiler and participates in the burning. The utility model discloses combine mud to mix the demand and the characteristics of the predrying treatment who burns, adopt the condensate water of thermal power generating unit backheating system to replace conventional flue gas, steam, carry out effective mummification to mud before mixing the burning, replace the higher grade heat source with the sludge drying heat source of lower grade, according to the quality distribution energy utilization, the thermodynamic perfectness of system is higher, can realize sludge drying and thermal power generating unit's organic coupling.

Description

Sludge mixed combustion system utilizing condensate water of thermal power generating unit for pre-drying

Technical Field

The utility model relates to a sludge treatment field especially relates to the sludge treatment field that combines with thermal power plant.

Background

Sludge is a common solid waste that requires purification. One mode of treating sludge in the prior art is to directly send the sludge into a incinerator for incineration or transport the sludge to the existing coal-fired power plant for mixed combustion power generation after drying treatment of different degrees, and the method has good economical efficiency and environmental protection. The sludge blending combustion of the existing coal-fired power plant or biomass power plant utilizes 3 processes of direct blending combustion, blending combustion after sludge is directly dried by smoke, blending combustion after sludge is indirectly dried by steam, and the like.

In the direct mixed combustion process, the simply dehydrated sludge can be directly mixed combusted to generate power, the water content of the simply dehydrated sludge is still high and generally exceeds 80%, and therefore, a large amount of water vapor can be generated during combustion, so that the smoke volume is greatly increased, the smoke exhaust temperature is increased, and the efficiency and the operation stability of the boiler are influenced. Meanwhile, in order to maintain the load required by the unit, more fuel needs to be added while blending combustion, so that more energy and economic losses are caused.

The direct drying of the flue gas adopts high-temperature and low-oxygen flue gas of a boiler as a heat source, waste flue gas generated after drying carries sludge fine particles and evaporated moisture to be discharged from a sludge dryer, gas-solid separation is realized through a cyclone separator, and the separated sludge particles are stacked in a dry sludge storage warehouse and then discharged through an air-lock feeder. The temperature of the flue gas is reduced to 100-200 ℃ from above 300 ℃, and then the flue gas is put into a pre-electric dedusting flue and is discharged after being treated. The direct drying technology of flue gas can select the high temperature flue gas or the exhaust smoke of the boiler, the heat source selection is flexible, but the extraction of the high temperature flue gas can possibly generate certain influence on a boiler heating system, and more transformation is needed to be carried out on a boiler flue. The selection of the high-temperature flue gas is more critical, the flue gas after dust removal has high temperature but large dust content, a conveying pipeline can be seriously abraded, and the requirement on the flue gas conveying pipeline is higher; the flue gas temperature after dust removal is lower, the using amount is larger, and the response of control is slower.

Steam extracted by a turbine of the unit is used as a heat source for steam drying, the steam is indirectly contacted with sludge in the sludge drying equipment for heat exchange, the heat released by the steam is changed into condensed water and then returns to a steam-water system of the unit, and the condensed water is cooled after the sludge is dried and then enters a sludge drying bin to be sent to a coal yard or is mixed with coal by a coal feeding belt to be sent to a coal pulverizing system. Most solid particles in waste gas generated in the sludge drying process are removed by a dust remover, the waste gas enters a condenser to exchange heat with cooling water, non-condensed waste gas is sent to a boiler to be burnt by a fan, and condensed waste water is sent to a waste water treatment plant to be treated and then is discharged after reaching the standard. The indirect steam drying generally extracts low-pressure extracted steam of a steam turbine, but the extracted steam energy grade is still high, and the indirect steam drying is not energy-saving in practice when used for drying sludge. Meanwhile, the steam utilization system is complex, and the investment and operation and maintenance costs are the highest among the three sludge co-combustion technologies.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides a sludge blending combustion system utilizing the condensate water of the thermal power generating unit for predrying, which comprises a boiler, a high-pressure cylinder of a steam turbine, a medium-pressure cylinder of the steam turbine, a low-pressure cylinder of the steam turbine, a condenser, a condensate pump, a low-pressure heater, a deaerator, a water feeding pump, a high-pressure heater, a generator, a water pump and a sludge dryer; wherein:

the boiler, the steam turbine high-pressure cylinder, the steam turbine intermediate-pressure cylinder, the steam turbine low-pressure cylinder and the generator jointly form a power production unit of the system, sludge and fuel are mixed and combusted in the boiler and release heat energy, and the heat energy is converted into kinetic energy through the power production unit and finally converted into electric energy to be output outwards;

the low-pressure heater, the deaerator, the high-pressure heater, the condenser, the condensate pump and the feed pump form a heat recovery system of the system thermal power generating unit;

the sludge dryer is a sludge pre-drying system, one branch of the sludge dryer leads out part of condensed water from the heat recovery system, the condensed water enters the sludge dryer and heats the sludge in the sludge dryer to pre-dry the sludge, and the cooled condensed water returns to the heat recovery system; the pre-dried sludge enters the boiler and participates in combustion.

Further, the low pressure heater comprises a # 5 low pressure heater; the branch is connected with the outlet of the condensed water pipeline of the No. 5 low-pressure heater, part of condensed water flowing out of the outlet of the condensed water pipeline of the No. 5 low-pressure heater is provided with flowing power by the water pump, is conveyed into the sludge dryer by a pipeline and exchanges heat with sludge, and then enters the drain pipeline of the No. 7 low-pressure heater by the pipeline to further return to the heat recovery system.

Further, the sludge dryer works under micro negative pressure, and the sludge and the condensed water perform countercurrent heat exchange.

Further, the sludge entering the sludge dryer comes from a sludge bin, is pre-dried and then enters the boiler to participate in combustion after being treated by a feeder and a sludge crusher.

Further, the boiler is a coal-fired boiler or a biomass boiler.

Further, most solid particles of waste gas generated in the drying process of the sludge in the sludge dryer are removed by a dust remover, the waste gas is cooled, the obtained non-condensable waste gas is sent to the boiler for incineration by a fan, and the condensed waste water is sent to a waste water treatment plant for treatment and then is discharged after reaching the standard.

Furthermore, the temperature of the condensed water entering the regenerative system of the sludge dryer is 120-130 ℃, and the temperature of the cooled condensed water is 70-80 ℃.

The utility model provides a sludge blending combustion system of thermal power generating unit condensate water predrying combines the demand and the characteristics of sludge blending combustion predrying treatment, adopts the condensate water of the thermal power generating unit heat recovery system to replace conventional flue gas and steam, and effectively dries the sludge before blending combustion; the lower grade sludge drying heat source is used for replacing a higher grade heat source, the energy utilization is distributed according to the quality, the thermodynamic perfection of the system is higher, and the organic coupling of the sludge drying and the thermal generator set can be realized. Compared with the reconstruction of a boiler heating surface and a flue or the reconstruction of steam extraction by a steam turbine, the reconstruction of a condensation water pipeline of a regenerative system of a thermal power generating unit is simpler and is easier to implement. Compared with a flue gas conveying system and a steam utilization system, the pipeline conveying system using water as a heat exchange medium has lower operation requirement and simpler operation control.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a sludge mixed combustion system for pre-drying condensed water of a thermal power generating unit.

Wherein, 1-boiler, 2-turbine high pressure cylinder, 3-turbine intermediate pressure cylinder, 4-turbine low pressure cylinder, 5-condenser, 6-condensate pump, 7-8# low pressure heater, 8-7# low pressure heater, 9-6# low pressure heater, 10-5# low pressure heater, 11-deaerator, 12-feed water pump, 13-3# high pressure heater, 14-2# high pressure heater, 15-1# high pressure heater, 16-generator, 17-water pump, 18-sludge drier

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention and do not require that the present invention must be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

In addition, in the description of the present invention, unless otherwise specified and limited, it is to be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, and for example, they may be mechanically or electrically connected, or they may be connected to each other within two elements, directly or indirectly through an intermediate medium, and those skilled in the art may understand the specific meanings of the above terms according to specific situations.

Further, in the description of any method below, any process or method description in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and the scope of the preferred embodiments of the present invention includes additional implementations in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the embodiments of the present invention.

The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.

It should be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system.

As shown in fig. 1, the embodiment discloses a sludge co-combustion system pre-dried by using condensed water of a thermal power generating unit, and the system comprises a boiler 1, a turbine high-pressure cylinder 2, a turbine intermediate-pressure cylinder 3, a turbine low-pressure cylinder 4, a condenser 5, a condensed water pump 6, low-pressure heaters 7-10, a deaerator 11, a feed water pump 12, high-pressure heaters 13-15, a generator 16, a water pump 17 and a sludge dryer 18.

The boiler 1, the turbine high-pressure cylinder 2, the turbine intermediate-pressure cylinder 3, the turbine low-pressure cylinder 4 and the generator 16 jointly form a power production unit of the system, sludge and fuel are mixed and combusted in the boiler 1 and heat energy is released, and the heat energy is converted into kinetic energy through the power production unit and finally converted into electric energy and output outwards. Specifically, the heat released by fuel combustion heats the flowing working medium water in the heating surface of the boiler 1 to a steam state, and then enters a high-pressure cylinder of the steam turbine, the high-parameter steam pushes blades of the steam turbine to rotate to do work, the steam turbine drags a generator, and the kinetic energy is converted into electric energy to be supplied to the outside. The high-pressure cylinder, the middle-pressure cylinder and the low-pressure cylinder of the steam turbine are coaxially arranged in a split cylinder mode, steam at the outlet of the high-pressure cylinder enters the boiler 1 to be reheated and then enters the middle-pressure cylinder, the reheated steam sequentially flows through the middle-pressure cylinder and the low-pressure cylinder, and the outlet steam becomes exhaust steam and is discharged into the condenser.

And the low-pressure heater 7-10, the deaerator 11, the high-pressure heater 13-15, the condenser 5, the condensate pump 6 and the feed pump 12 form a heat recovery system of the thermal power generating unit of the system. The steam turbine is provided with a three-level high-pressure heater, a four-level low-pressure heater, a deaerator and a condenser, steam extracted from each level of the steam turbine is subjected to heat release and condensation in the regenerative heater, formed drainage automatically flows to the next-level regenerative heater through a pipeline, and drainage of the high-pressure heater is finally collected into the deaerator; the drained water of the low-pressure heater is finally collected into a hot well of the condenser; the exhaust steam flowing into the condenser is condensed and collected in a condenser hot well, and is conveyed by a pipeline to flow through low-pressure regenerative heaters of all stages after being boosted by a condensate pump 6; the condensed water flowing through the last stage of low-pressure heater flows into the deaerator for deaerating one way, then flows through the high-pressure heaters in sequence after being boosted by the water feeding pump 12, and the other branch enters the sludge dryer 18.

The sludge dryer 18 is a sludge pre-drying system, the condensed water flowing through the last stage of low-pressure heater enters the sludge dryer 18 from a branch and heats the sludge in the sludge dryer 18 to perform sludge pre-drying, and the cooled condensed water returns to the heat recovery system; the pre-dried sludge enters the boiler 1 and participates in combustion.

In a specific embodiment, the low-pressure heaters include a # 8 low-pressure heater 7, a # 7 low-pressure heater 8, a # 6 low-pressure heater 9 and a # 5 low-pressure heater 10, the branch is connected to an outlet of a condensed water pipe of the # 5 low-pressure heater 10, a part of condensed water flowing out of the outlet of the condensed water pipe of the # 5 low-pressure heater 10 is provided with flowing power by the water pump 17, is conveyed to the sludge dryer 18 by a pipeline, exchanges heat with sludge, and then enters a drain pipe of the # 7 low-pressure heater 8 by a pipeline to return to the regenerative system.

In a particular embodiment, the sludge dryer 18 operates at a slight negative pressure, and the sludge is subjected to countercurrent heat exchange with the condensate.

In a specific embodiment, the sludge entering the sludge dryer 18 comes from a sludge bin, is pre-dried, is treated by a feeder and a sludge crusher, and then enters the boiler 1 to participate in combustion.

In a specific embodiment, the boiler 1 is a coal-fired boiler or a biomass boiler.

Specifically, most solid particles of waste gas generated in the drying process of the sludge in the sludge dryer 18 are removed by a dust remover, the waste gas is cooled, the obtained non-condensable waste gas is sent to the boiler 1 by a fan for incineration, and the condensed waste water is sent to a waste water treatment plant for treatment and then is discharged after reaching the standard.

Specifically, the temperature of the condensed water entering the regenerative system of the sludge dryer 18 is 120-130 ℃, and the temperature of the cooled condensed water is 70-80 ℃.

The sludge mixed combustion system utilizing the pre-drying of the condensed water of the thermal power generating unit disclosed by the embodiment can realize the following technical effects:

1. low-pressure condensed water of a turbine heat recovery system of the thermal power generating unit is extracted to pre-dry sludge, so that the sludge is effectively dried, and the problem that the boiler efficiency is reduced due to high sludge moisture is avoided;

2. the condensed water is used as a heat source for pre-drying the sludge, compared with the traditional flue gas and steam which are used as heat sources, the grade of the utilized energy is reduced, and the energy utilization is more reasonable; the high-grade heat of the high-temperature flue gas and the low-pressure extracted steam is absorbed by working medium water of Rankine cycle of the steam turbine and further converted into electric energy, so that the power generation efficiency of the thermal power generating unit is improved;

3. the condensed water is used as a heat source for drying the sludge, and is transported by a pipeline, so that the requirement on pipeline materials is reduced compared with the transportation of flue gas and steam; compared with a flue gas conveying system and a steam utilization system, the pipeline conveying system using water as a heat exchange medium has the advantages of lower operation requirement and simpler control.

4. The condensate water of the regenerative system of the thermal power generating unit has higher water temperature and larger water amount, meets the requirement of sludge drying, simultaneously utilizes the water supply deoxidization and chemical water treatment system of the water circulation of the thermal power generating unit, has higher water quality, and avoids causing the scaling blockage and corrosion inside the transportation pipeline.

5. The condensed water of the regenerative system of the thermal power generating unit is used as a heat source, and compared with the method of using flue gas and steam extracted by a steam turbine as drying heat sources, the method has the advantages of low modification cost and low operation and maintenance cost.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (7)

1. The utility model provides an utilize sludge of thermal power generating unit condensate water predrying to mix system of burning which characterized in that: the system comprises a boiler (1), a turbine high-pressure cylinder (2), a turbine intermediate-pressure cylinder (3), a turbine low-pressure cylinder (4), a condenser (5), a condensate pump (6), low-pressure heaters (7-10), a deaerator (11), a water feed pump (12), high-pressure heaters (13-15), a generator (16), a water pump (17) and a sludge dryer (18); wherein:

the boiler (1), the steam turbine high-pressure cylinder (2), the steam turbine intermediate-pressure cylinder (3), the steam turbine low-pressure cylinder (4) and the generator (16) jointly form a power production unit of the system, sludge and fuel are mixed and combusted in the boiler (1) and release heat energy, and the heat energy is converted into kinetic energy through the power production unit and finally converted into electric energy to be output outwards;

the low-pressure heaters (7-10), the deaerator (11), the high-pressure heaters (13-15), the condenser (5), the condensate pump (6) and the feed pump (12) form a heat recovery system of the system thermal power unit;

the sludge dryer (18) is a sludge pre-drying system, one branch of the sludge dryer (18) leads out part of condensed water from the heat recovery system, the condensed water enters the sludge dryer (18) and heats the sludge in the sludge dryer to carry out sludge pre-drying, and the cooled condensed water returns to the heat recovery system; the pre-dried sludge enters the boiler (1) and participates in combustion.

2. The system of claim 1, wherein: the low-pressure heater comprises a No. 8 low-pressure heater (7); the branch circuit is connected with the outlet of a condensed water pipeline of the No. 5 low-pressure heater (10), part of condensed water flowing out of the outlet of the condensed water pipeline of the No. 5 low-pressure heater (10) is provided with flowing power by the water pump (17), is conveyed into the sludge dryer (18) by a pipeline and exchanges heat with sludge, and then enters a drain pipeline of the No. 7 low-pressure heater (8) by the pipeline to further return to the heat recovery system.

3. The system of claim 1, wherein: the sludge dryer (18) works under micro negative pressure, and the sludge and the condensed water perform countercurrent heat exchange.

4. The system of claim 1, wherein: the sludge entering the sludge dryer (18) comes from a sludge bin, is pre-dried, is treated by a feeder and a sludge crusher, and then enters the boiler (1) to participate in combustion.

5. The system of claim 1, wherein: the boiler (1) is a coal-fired boiler or a biomass boiler.

6. The system of claim 1, wherein: most solid particles of waste gas generated in the drying process of the sludge in the sludge dryer (18) are removed by a dust remover, the waste gas is cooled, the obtained non-condensed waste gas is sent to the boiler (1) by a fan for incineration, and the condensed waste water is sent to a waste water treatment plant for treatment and then is discharged after reaching the standard.

7. The system of claim 1, wherein: the temperature of the condensed water entering the regenerative system of the sludge dryer (18) is 120-130 ℃, and the temperature of the cooled condensed water is 70-80 ℃.

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