CN115899716A - Thermal power plant flue gas-sludge-solar energy comprehensive gradient utilization system and method - Google Patents
Thermal power plant flue gas-sludge-solar energy comprehensive gradient utilization system and method Download PDFInfo
- Publication number
- CN115899716A CN115899716A CN202211365471.3A CN202211365471A CN115899716A CN 115899716 A CN115899716 A CN 115899716A CN 202211365471 A CN202211365471 A CN 202211365471A CN 115899716 A CN115899716 A CN 115899716A
- Authority
- CN
- China
- Prior art keywords
- sludge
- hot air
- flue gas
- heat
- circulating hot
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The invention discloses a comprehensive cascade utilization system and a method of flue gas-sludge-solar energy of a thermal power plant, wherein the system comprises: the boiler is used for providing heat energy for the thermal power plant; the boiler is provided with a high-temperature flue gas outlet and a raw material inletA material port; the air preheater is used for preheating air by utilizing the waste heat of high-temperature flue gas discharged by the boiler; the absorption heat pump is used for converting a small amount of high-grade high-temperature flue gas heat into a large amount of low-grade circulating hot air heat and cold water cold; the solar heating system is used for collecting solar heat energy and converting the solar energy into heat energy; the sludge drying system comprises at least two stages of sludge drying machines which are sequentially connected in series, and the sludge drying machines at all stages sequentially dry and transmit sludge. The invention realizes the gradient utilization of the waste heat of the flue gas and the harmless treatment of the sludge, and not only the energy utilization rate of the system and the sludge
The efficiency is improved, and the consumption of circulating cold water and fire coal can be reduced, so that the economy and the environmental protection of an energy system of a thermal power plant are improved.
Description
Technical Field
The invention relates to the technical field of flue gas waste heat utilization and sludge treatment, in particular to a thermal power plant flue gas-sludge-solar energy comprehensive gradient utilization system and a method.
Background
With the increasing energy demand, the energy structure system needs to be promoted to reform, a novel environment-friendly energy-saving technology is developed, and the existing energy conversion technology is subjected to energy-saving environment-friendly modification and upgrading. The thermal power plant is a large household for energy production and consumption, and the heat loss of exhaust smoke accounts for the largest percentage of all heat loss indexes of a boiler of the thermal power plant, and is about 50%. The heat release quantity of the unit temperature drop of the boiler exhaust smoke is larger than the heat absorption quantity of the unit temperature rise of the boiler air supply, so that the smoke on the smoke outlet side of the air preheater still has higher temperature (up to 150 ℃), and a large amount of heat is wasted. The effective utilization of the part of flue gas energy is realized through a proper technical means, and the heat utilization rate of a thermal power plant can be improved, and the energy-saving and environment-friendly level can be improved.
On the other hand, the harmless treatment of sludge is an important issue of current environmental research, and has important significance for environmental protection and ecological safety. The sludge has dual attributes of pollution and resources, and the sludge is subjected to high-dryness dehydration and then is subjected to synergistic combustion with the pulverized coal, so that the self heat value of the sludge can be utilized, the coal consumption is reduced, pathogenic microorganisms in the sludge can be completely treated in a high-temperature incineration mode, and the harmless treatment of the sludge is realized.
In recent years, the boiler of the thermal power plant has attracted extensive attention, but the prior art mainly focuses on the feasibility of the synergistic combustion after the sludge is dried by utilizing the exhaust gas of the boiler or high-temperature steam, and the proposed system still has certain defects:
1) The wet sludge is dried by directly utilizing high-temperature exhaust smoke of the boiler at about 250 ℃, and a large amount of organic matter volatile malodorous gas is generated in the sludge at the temperature to cause air pollution.
2) During the drying process, the high-temperature exhaust smoke and the low-temperature sludge have larger heat exchange temperature difference, and the irreversible loss is larger.
3) The energy gradient utilization level of the system is low, and a large amount of heat in the high-temperature flue gas cannot be effectively utilized, so that the waste of heat energy is caused.
4) Only the wet sludge is subjected to primary drying, and the wet sludge subjected to primary drying still contains moisture, so that the combustion efficiency is low when the moisture is directly introduced into a boiler for combustion. And the wet sludge is dried by adopting a heat source independently, and additional coal consumption is needed.
Disclosure of Invention
Therefore, the invention aims to solve the technical problems that the energy cascade utilization level of the system in the prior art is low and the combustion efficiency is low due to the fact that only wet sludge is subjected to primary drying, so that the environment-friendly and energy-saving performance of the thermal power plant is improved.
In order to achieve the purpose, the invention adopts the technical scheme that:
a flue gas-sludge-solar energy comprehensive cascade utilization system of a thermal power plant comprises:
the boiler is used for providing heat energy for the thermal power plant; the boiler is provided with a high-temperature flue gas outlet and a raw material inlet;
the air preheater is communicated with a high-temperature flue gas outlet of the boiler through a main flue and is used for preheating air by using the waste heat of the high-temperature flue gas discharged by the boiler;
the absorption heat pump is communicated with and arranged on the side part of the main flue through a bypass flue and is used for converting a small amount of high-grade high-temperature flue gas heat into a large amount of low-grade circulating hot air heat and cold water cold;
the solar heating system is used for collecting solar heat energy and converting the solar energy into heat energy;
the sludge drying system comprises at least two stages of sludge drying machines which are sequentially connected in series, wherein the sludge drying machines at all stages sequentially dry and transmit sludge; the primary sludge drying machine heats the sludge through the absorption heat pump, the secondary sludge drying machines heat the sludge through the solar heating system, and the secondary sludge drying machine at the tail part can input the dried sludge into the boiler for incineration.
Optionally, the absorption heat pump comprises:
the generator is internally provided with a cavity shape and a flue gas pipe network communicated with the bypass flue;
the interior of the absorber is arranged to be cavity-shaped and is provided with a first circulating hot air pipe network, and the first circulating hot air pipe network is communicated with a hot air outlet of the primary sludge drying machine; the inner cavity of the generator is communicated with the inner cavity of the absorber through a dilute absorption solution circulating system;
the interior of the condenser is arranged to be cavity-shaped and is provided with a second circulating hot air pipe network communicated with the first circulating hot air pipe network, and the second circulating hot air pipe network is communicated with a hot air inlet of the primary sludge drying machine; a high-temperature steam outlet of the generator is communicated with an inner cavity of the condenser;
the evaporator is internally provided with a cavity and a cold water pipe network for introducing cold water; and a condensed water outlet of the condenser is communicated with an inner cavity of the evaporator, and a low-temperature and low-pressure water vapor outlet of the evaporator is communicated with an inner cavity of the absorber.
Optionally, the primary circulating hot air system includes:
one end of the primary circulating hot air outlet pipe is communicated with a hot air outlet of the second circulating hot air pipe network, and the other end of the primary circulating hot air outlet pipe is communicated with the primary sludge drier;
one end of the primary circulating hot air inlet pipe is communicated with the primary sludge drier, and the other end of the primary circulating hot air inlet pipe is communicated with a hot air inlet of the first circulating hot air pipe network;
the first drying pipe is arranged on the primary circulating hot air inlet pipe and is used for drying the primary circulating air output from the primary sludge drying machine;
and the first circulating pump is arranged on the primary circulating hot air inlet pipe.
Optionally, the primary sludge drying machine is communicated with a wet sludge conveying mechanism for inputting sludge.
Optionally, the solar heating system comprises:
the secondary circulating hot air pipe is circularly and hermetically connected and arranged on the secondary sludge drying machine and used for conveying secondary circulating hot air; the secondary circulating hot air pipe is provided with a shutoff valve and a first flow regulating valve;
the solar air heat collector is arranged on the secondary circulating hot air pipe and used for collecting medium-high temperature solar heat energy and heating the secondary circulating hot air;
the second circulating pump is arranged on the secondary circulating hot air pipe;
and the second drying pipe is arranged on the secondary circulating hot air pipe and is used for drying the secondary circulating hot air.
Optionally, the second-stage circulating hot air pipe is connected in parallel and communicated with a second-stage circulating hot air branch pipe, and the second-stage circulating hot air branch pipe is provided with:
the heat storage equipment can store redundant heat when solar energy resources are rich and release heat when the solar energy resources are insufficient at night;
a third circulation pump;
and the second flow regulating valve is used for regulating the secondary circulating hot air quantity input to the heat storage equipment.
Optionally, a medium-temperature phase change material is arranged inside the heat storage device.
Optionally, the method further includes:
and the tail gas treatment system is used for treating the tail gas exhausted from the air preheater and the absorption heat pump.
Optionally, the exhaust gas treatment system comprises:
the dust remover is communicated with the air outlet end of the air preheater and the air outlet end of the flue gas pipe network and is used for removing dust from the flue gas;
the flue gas desulfurization and denitrification device is communicated with the gas outlet end of the dust remover and is used for desulfurization and denitrification of flue gas;
the exhaust pipeline is communicated with the gas outlet end of the flue gas desulfurization and denitrification device;
the induced draft fan is arranged on the exhaust pipeline;
and the chimney is communicated with the tail end of the exhaust pipeline and is used for exhausting tail gas.
A comprehensive cascade utilization method of flue gas-sludge-solar energy of a thermal power plant is carried out based on the comprehensive cascade utilization system of flue gas-sludge-solar energy of the thermal power plant, and comprises the following steps:
s1, dividing high-temperature flue gas generated by a boiler into two parts: one part of high-temperature flue gas enters an air preheater through a main flue to exchange heat with air, and the other part of high-temperature flue gas enters a generator of the absorption heat pump through a bypass flue;
s2, the absorption heat pump takes high-temperature flue gas of a bypass flue as a high-temperature driving heat source, takes cold water as a low-temperature heat source, and heats primary circulating hot air by absorbing heat of the high-temperature flue gas and the cold water; introducing cold water into an evaporator of the absorption heat pump for cooling, and then introducing the cold water into a cooling tower for cooling the unit;
s3, sequentially conveying the sludge into sludge drying machines at all levels to carry out drying and heating step by step under the conveying of a wet sludge conveying mechanism, and finally conveying the sludge into a boiler to be mixed with coal and then burning the mixture;
wherein the primary sludge drying machine heats the sludge through an absorption heat pump; and each secondary sludge drying machine heats the sludge through a solar heating system.
Optionally, in step S3, the step of heating the sludge by the primary sludge drying machine through the absorption heat pump is as follows:
in a primary sludge drying machine, primary circulating hot air from a condenser in an absorption heat pump is used for drying and heating sludge; the hot air from the outlet of the primary sludge drier is dried by the first drying pipe and then enters the absorber of the absorption heat pump again to obtain heat.
Optionally, in step S3, the step of heating the sludge by each secondary sludge drying machine through the solar heating system respectively is as follows:
secondary circulating hot air from a hot air outlet of the secondary sludge drying machine enters a second drying pipe for drying, enters a solar air heat collector under the action of a second circulating pump to obtain heat, and returns to a hot air inlet of the secondary sludge drying machine;
or secondary circulating hot air from the hot air outlet of the secondary sludge drying machine enters the second drying pipe for drying, enters the heat storage equipment again under the action of the third circulating pump to obtain heat, and returns to the hot air inlet of the secondary sludge drying machine.
Optionally, the method further comprises a tail gas treatment step:
the flue gas coming out from the flue gas outlets of the absorption heat pump and the air preheater is gathered and then sequentially passes through the dust remover and the flue gas desulfurization and denitrification device, and is discharged into the atmospheric environment from the chimney under the action of the draught fan after reaching the discharge standard.
The technical scheme of the invention has the following advantages:
1. the invention provides a flue gas-sludge-sun for a thermal power plantThe comprehensive cascade utilization system realizes cascade utilization of flue gas waste heat and harmless treatment of sludge through the synergistic effect among a newly introduced solar heating system, a sludge drying system and an absorption heat pump on the basis of the traditional heat-engine plant energy system, and not only is the energy utilization rate of the system and the harmless treatment of the sludge realized
The efficiency is improved, and the consumption of circulating cold water and fire coal can be reduced, so that the economy and the environmental protection of an energy system of a thermal power plant are improved.
The invention improves the environmental protection and energy saving performance of the thermal power plant, and realizes the multi-energy complementation of the energy system of the thermal power plant and the harmless treatment of the sludge by combining the energy technologies of flue gas waste heat gradient utilization, sludge mixed combustion, solar heat collection, heat storage and the like based on the principles of temperature matching and grade matching, thereby improving the comprehensive energy utilization rate and the economic environmental protection performance of the system.
2. According to the comprehensive cascade utilization system of the flue gas, the sludge and the solar energy of the thermal power plant, provided by the invention, part of the flue gas is extracted through the bypass flue and is used as a high-temperature heat source for driving the absorption heat pump, so that the heat release amount of unit temperature drop during boiler smoke exhaust and the heat absorption amount of unit temperature rise during boiler air supply can be better matched, and the irreversible loss in the air preheater is reduced.
3. According to the comprehensive cascade utilization system of the flue gas, the sludge and the solar energy of the thermal power plant, the absorption heat pump absorbs heat of high-temperature flue gas and cold water, so that primary circulating hot air is heated. By the mode, a small amount of high-grade high-temperature flue gas heat is converted into a large amount of low-grade primary circulating hot air heat and cold water cold, and huge heat exchange temperature difference caused by direct sludge drying of high-temperature flue gas can be avoided
The system can reduce the loss and the atmospheric pollution, can also improve the energy utilization rate of the system, and can reduce the temperature of cold water while increasing the heat supply of primary circulating hot air for sludge drying, thereby meeting the requirements of the same cooling load on the cold water consumed by a cooling towerThe amount is reduced, and the economic efficiency and the environmental protection performance of the system are improved.
4. According to the comprehensive gradient utilization system of the flue gas, the sludge and the solar energy of the thermal power plant, provided by the invention, through coupling the photo-thermal and heat storage equipment, the energy consumed by sludge drying is reduced, and all-weather continuous drying of the sludge is realized.
5. According to the comprehensive cascade utilization system of the flue gas, the sludge and the solar energy of the thermal power plant, provided by the invention, the sludge is gradually dried and heated in a multi-stage sludge drying mode, so that irreversible loss caused by temperature alignment and heat exchange temperature difference in the heat exchange process is reduced, and the improvement of the system is facilitated
Efficiency and energy conservation; and through the mode of multistage sludge drying, the moisture that exists in the wet mud is greatly reduced, improves mud combustion efficiency, because utilize solar energy to carry out the drying to mud, need not additionally to consume the fire coal to the drying of mud.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic structural diagram of a comprehensive cascade utilization system of flue gas-sludge-solar energy of a thermal power plant;
fig. 2 is a schematic structural diagram of an absorption heat pump in the flue gas-sludge-solar comprehensive cascade utilization system of the thermal power plant.
Reference numerals:
1. a boiler; 2. an air preheater; 3. an absorption heat pump; 31. an absorber; 32. a delivery pump; 33. a generator; 34. a condenser; 35. a pressure reducing valve; 36. an evaporator; 4. a dust remover; 5. a flue gas desulfurization and denitrification device; 6. an induced draft fan; 7. a chimney; 8. a cooling tower; 9. a solar air collector; 10. a heat storage device; 11. a wet sludge bin; 12. a screw conveyor; 13. a primary sludge drier; 14. a secondary sludge drier; 15. a first drying duct; 16. a second drying duct; 17. a first circulation pump; 18. a second circulation pump; 19. a third circulation pump; 20. a first flow regulating valve; 21. a second flow regulating valve; 22. closing the valve; a. a dilute absorbing solution; b. high-temperature high-pressure steam; c. a concentrated absorption solution; d. and (5) low-temperature condensation water.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Furthermore, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Example 1
A specific embodiment of a flue gas-sludge-solar comprehensive cascade utilization system of a thermal power plant as shown in fig. 1 comprises a boiler 1, an air preheater 2, an absorption heat pump 3, a solar heating system and a sludge drying system.
The boiler 1 is used for burning the fuel mixed with the dried sludge and the coal, so that high-temperature steam is generated to be used as a raw material for power generation of a thermal power plant, and the fuel is changed into high-temperature flue gas after being burnt and is discharged from a flue. The boiler 1 is provided with a high-temperature flue gas outlet and a raw material inlet. The high-temperature flue gas outlet is arranged at the bottom of the boiler 1, and the raw material inlet is arranged at the side part of the boiler 1.
The air preheater 2 is communicated with a high-temperature flue gas outlet of the boiler 1 through a main flue and is used for preheating air by using the waste heat of the high-temperature flue gas discharged by the boiler 1, wherein a flue gas inlet of the air preheater 2 is communicated with a flue gas outlet of the boiler through the main flue, and a flue gas outlet of the air preheater is communicated with a dust remover.
The absorption heat pump 3 is communicated with and arranged at the side part of the main flue through a bypass flue and is used for converting a small amount of high-grade high-temperature flue gas heat into a large amount of low-grade circulating hot air heat and cold water cold.
Solar heating systems are used to collect solar thermal energy and convert the solar energy into thermal energy.
The sludge drying system comprises at least two stages of sludge drying machines which are sequentially connected in series, wherein the sludge drying machines at all stages sequentially dry and transmit sludge; the primary sludge drying machine heats sludge through the absorption heat pump 3, each secondary sludge drying machine heats sludge through the solar heating system, and the secondary sludge drying machine at the tail part can input dried sludge into the boiler 1 for incineration.
According to the step utilization system for flue gas-sludge-solar energy synthesis of the thermal power plant, the embodiment is based on the traditional energy system of the thermal power plant through new introductionThe synergistic effect among the solar heating system, the sludge drying system and the absorption heat pump realizes the cascade utilization of the waste heat of the flue gas and the harmless treatment of the sludge, and not only the energy utilization rate of the system and the harmless treatment of the sludge are realized
The efficiency is improved, and the consumption of circulating cold water and fire coal can be reduced, so that the economical efficiency and the environmental protection property of an energy system of a thermal power plant are improved.
The primary sludge drying machine provided by the invention utilizes primary circulating hot air to dry sludge. The sludge outlet of the first-stage sludge drying machine is communicated with the inlet of the second-stage sludge drying machine, and the two-stage sludge drying machine or the multi-stage sludge drying machine can be arranged in the embodiment. The secondary sludge drier dries sludge by using secondary circulating hot air. The sludge outlet of the secondary sludge drying machine in the embodiment is communicated with the sludge inlet of the boiler.
The absorption heat pump 3 of the present invention uses high temperature flue gas of a boiler as a high temperature driving heat source, and uses cold water as a low temperature heat source to heat primary circulating hot air. The absorption heat pump heats the primary circulating hot air by absorbing heat in the high-temperature flue gas and the cold water. By the mode, a small amount of high-grade high-temperature flue gas heat is converted into a large amount of low-grade primary circulating hot air heat and cold water cold, and huge heat exchange temperature difference caused by direct sludge drying of high-temperature flue gas can be avoided
The system can also improve the energy utilization rate of the system, and the temperature of cold water is reduced when the primary circulating hot air for drying sludge is increased in heat supply, so that the amount of cold water consumed by a cooling tower is reduced under the condition of meeting the requirement of the same cooling load, and the economic efficiency and the environmental protection performance of the system are improved.
As shown in fig. 2, the absorption heat pump 3 of the present invention includes a generator 33, an absorber 31, a condenser 34, and an evaporator 36.
The generator 33 is internally provided with a cavity shape and a flue gas pipe network communicated with the bypass flue, so that the generator is communicated with a boiler flue gas outlet, and the generator flue gas outlet is communicated with the dust remover inlet.
The absorber 31 is provided with a first circulating hot air pipe network in a cavity shape, and the first circulating hot air pipe network is communicated with a hot air outlet of the primary sludge drying machine. The inner cavity of the generator 33 is communicated with the inner cavity of the absorber 31 through a weak absorption solution circulating system. More specifically, the absorber hot air inlet is communicated with the first drying pipe hot air outlet.
The interior of the condenser 34 is designed into a cavity shape and is provided with a second circulating hot air pipe network communicated with the first circulating hot air pipe network, and the second circulating hot air pipe network is communicated with a hot air inlet of the primary sludge drying machine. The high-temperature steam outlet of the generator 33 is communicated with the inner cavity of the condenser 34.
The interior of the evaporator 36 is provided in the shape of a cavity and provided with a cold water pipe network. One end of the cold water pipe network is communicated with cold water, and the other end of the cold water pipe network is communicated with a cold water inlet of the cooling tower. The cooling tower is used for cooling the unit and keeping the unit stably running.
The condensed water outlet of the condenser 34 is communicated with the inner cavity of the evaporator 36, and the low-temperature and low-pressure water vapor outlet of the evaporator 36 is communicated with the inner cavity of the absorber 31.
In addition, the present invention further includes a pressure reducing valve 35 on a connection line between the condensed water outlet of the condenser 34 and the inner cavity of the evaporator 36, and the condensed water discharged from the condenser 34 can be further cooled by the pressure reducing valve 35.
The working principle of the absorption heat pump is as follows:
the dilute absorbing solution a from the absorber 31 is passed to the generator 33 by means of the transfer pump 32. The generator 33 uses the high-temperature flue gas of the bypass flue as a driving heat source to heat and concentrate the dilute absorption solution a to generate high-temperature high-pressure steam b and concentrated absorption solution c, and the temperature of the high-temperature flue gas is reduced and discharged from the generator 33. The high-temperature and high-pressure steam b enters the condenser 34 to release heat and becomes low-temperature condensed water d; the low-temperature condensed water is further reduced in temperature by the pressure reducing valve 35 and then introduced into the evaporator 36 to be low-temperature evaporated to generate low-temperature low-pressure water vapor e, and the evaporation process absorbs heat from external cold water to reduce the temperature of the external cold water. Finally, the low-temperature and low-pressure water vapor e and the concentrated absorption solution c from the absorber 31 enter the absorber together to be mixed, so that the heat is released while the dilute absorption solution a is generated, and the circulation of the absorption solution is completed.
For the primary circulating hot air, the heat released in the processes of solution mixing and high-temperature steam condensation is absorbed in the absorber 31 and the condenser 34 in sequence, and then the primary circulating hot air is discharged and enters a hot air inlet of the primary sludge drying machine. Therefore, the absorption heat pump utilizes the working capacity of high-grade waste heat to transfer heat in high-temperature flue gas and external cold water to the primary circulating hot air, so that on one hand, the heating capacity of the circulating hot air is increased, the sludge drying capacity is favorably improved, on the other hand, the cold capacity of unit cold water is increased, and further the cold water consumption of the cooling tower is favorably reduced.
The primary circulating hot air system comprises a primary circulating hot air outlet pipe, a primary circulating hot air inlet pipe, a first drying pipe 15 and a first circulating pump 17.
One end of the primary circulating hot air outlet pipe is communicated with a hot air outlet of the second circulating hot air pipe network, and the other end of the primary circulating hot air outlet pipe is communicated with the primary sludge drier.
One end of the primary circulating hot air inlet pipe is communicated with the primary sludge drier, and the other end of the primary circulating hot air inlet pipe is communicated with a hot air inlet of the first circulating hot air pipe network.
The first drying pipe 15 is arranged on the primary circulating hot air inlet pipe and used for drying the primary circulating air output from the primary sludge drying machine.
The first circulating pump 17 is arranged on the primary circulating hot air inlet pipe and used for pumping the primary circulating hot air.
The primary sludge drying machine is communicated with a wet sludge conveying mechanism for inputting sludge. The wet sludge conveying mechanism comprises a wet sludge bin 11 and a screw conveyor 12. The wet sludge bin 11 is used for storing wet sludge. The screw conveyor 12 is used for conveying sludge, and a sludge outlet of the screw conveyor 12 is communicated with a sludge inlet of the primary sludge drying machine 13.
Further, the solar heating system of the present invention comprises a secondary circulation hot air pipe, a solar air collector 9, a shut-off valve 22, a first flow control valve 20, a second circulation pump 18, and a second drying pipe 16.
The secondary circulating hot air pipe is circularly and hermetically connected with the secondary sludge drying machine and is used for conveying secondary circulating hot air. The secondary circulation hot air pipe is provided with a shut-off valve 22 and a first flow regulating valve 20. The shutoff valve 22 is used for controlling the on-off of the secondary circulation hot air pipe, and the shutoff valve 22 plays a role in opening and closing and is used for switching pipelines in the daytime and at night. The first flow regulating valve 20 is used for regulating the flow on the secondary circulating hot air pipe, and further regulating the secondary circulating hot air quantity input into the secondary sludge drying machine in the daytime.
The solar air heat collector 9 is arranged on the secondary circulating hot air pipe and used for collecting medium-high temperature solar heat energy and heating secondary circulating hot air. The second circulating pump 18 is disposed on the secondary circulating hot air duct for driving the secondary circulating hot air during the daytime. The second drying pipe 16 is arranged on the secondary circulating hot air pipe and is used for drying the secondary circulating hot air.
The second-stage circulating hot air pipe is connected in parallel and communicated with a second-stage circulating hot air branch pipe, and the second-stage circulating hot air branch pipe is provided with a heat storage device 10, a third circulating pump 19 and a second flow regulating valve 21. The heat storage device 10 can store surplus heat when solar resources are abundant and release heat when solar resources are insufficient at night. The third circulation pump 19 is used to drive the secondary circulation hot air at night. The second flow regulating valve 21 is used for regulating the amount of the two-stage circulating hot air input to the heat storage device 10. By coupling the photo-thermal and heat storage equipment, the energy consumed by drying the sludge is reduced, and all-weather continuous drying of the sludge is realized.
As a modified embodiment, the heat storage device 10 in this embodiment is provided with a medium-temperature phase change material inside. When solar energy resources are rich, high-temperature secondary circulating hot air from the outlet of the solar air heat collector enters the heat storage device to release heat to the phase-change material, the phase-change material is changed from a solid state to a liquid state, so that redundant heat is stored, and the secondary circulating hot air with the reduced temperature at the outlet of the heat storage device enters the solar air heat collector again to continue circulation. When solar energy resources are insufficient at night and the like, low-temperature secondary circulating hot air from the outlet of the second drying pipe enters the heat storage device to absorb heat, the phase-change material is changed from a liquid state to a solid state, so that the stored heat is released, the temperature of the secondary circulating hot air rises through the heat storage device, and the secondary circulating hot air with the raised temperature output from the outlet of the heat storage device enters the secondary sludge drying machine again to continue to circulate. And continuous operation of the whole system is realized through the heat storage equipment.
As a modified embodiment, the present embodiment further includes an exhaust gas treatment system, which is used to treat the exhaust gas exhausted from the air preheater 2 and the absorption heat pump 3.
The tail gas treatment system comprises a dust remover 4, a flue gas desulfurization and denitrification device 5, an exhaust pipeline, an induced draft fan 6 and a chimney 7.
The dust remover 4 is communicated with the air outlet end of the air preheater 2 and the air outlet end of the flue gas pipe network and is used for removing dust from the flue gas.
The flue gas desulfurization and denitration device 5 is communicated with the gas outlet end of the dust remover 4 and is used for desulfurization and denitration of flue gas so as to reach the emission standard. The exhaust pipeline is communicated with the gas outlet end of the flue gas desulfurization and denitrification device 5.
The induced draft fan 6 is arranged on the exhaust pipeline and used for pumping out the flue gas in the boiler and introducing the flue gas treated by the flue gas desulfurization and denitrification device 5 into the chimney 7.
The chimney 7 is communicated with the tail end of the exhaust pipeline, is vertically arranged and is used for exhausting tail gas.
In this embodiment, remove dust, SOx/NOx control to the flue gas through tail gas processing system, and then the atmosphere of discharging has avoided appearing the direct evacuation of boiler flue gas and has caused the problem of pollution to the environment.
Example 2
The embodiment discloses a specific implementation mode of a thermal power plant flue gas-sludge-solar comprehensive cascade utilization method, which is performed based on the thermal power plant flue gas-sludge-solar comprehensive cascade utilization system in embodiment 1 and comprises the following steps:
s1, high-temperature flue gas generated by a boiler 1 is divided into two parts: one part of high-temperature flue gas enters the air preheater 2 through the main flue to exchange heat with air, and the other part of high-temperature flue gas enters the generator 33 of the absorption heat pump 3 through the bypass flue to serve as a high-temperature driving heat source. Because the amount of flue gas entering the air preheater is reduced, the heat release amount of unit temperature drop during boiler smoke exhaust and the heat absorption amount of unit temperature rise during boiler air supply are better matched, and the irreversible loss in the air preheater 2 is reduced.
S2, the absorption heat pump 3 takes high-temperature flue gas of the bypass flue as a high-temperature driving heat source, takes cold water as a low-temperature heat source, and heats the primary circulating hot air by absorbing heat of the high-temperature flue gas and the cold water. By the mode, a small amount of high-grade high-temperature flue gas heat is converted into a large amount of low-grade primary circulating hot air heat and cold water cold, and huge heat exchange temperature difference caused by direct sludge drying of high-temperature flue gas can be avoided
The air pollution is reduced, and the energy utilization rate of the system can be improved. Cold water is introduced into the evaporator of the absorption heat pump 3 to be cooled and then enters the cooling tower 8 to cool the unit, and the temperature of the cold water is reduced while the heat supply of the primary circulating hot air for drying sludge is increased, so that the amount of the cold water consumed by the cooling tower 8 is reduced under the condition of meeting the requirement of the same cooling load.
S3, sludge in the wet sludge bin 11 is sequentially dried and heated step by the first-stage sludge drying machine 13 and the sludge drying machines of all stages under the action of the screw conveyor 12, and is finally sent into the boiler 1 to be mixed with coal and then combusted.
Wherein, the first-level sludge drying machine heats the sludge through the absorption heat pump 3, and the specific steps are as follows:
in the primary sludge drier, primary circulating hot air from a condenser 34 in the absorption heat pump 3 is used for drying and heating sludge, and the temperature of the primary circulating hot air is relatively low, so that the sludge is dried and heated due to the heat exchange temperature difference
The loss is small. From the first sludgeAfter being dried by the first drying pipe 15, the hot air at the outlet of the evaporator enters the absorber 31 of the absorption heat pump again under the action of the first circulating pump 17 to obtain heat.
And the other sludge drying machines at all levels connected with the first-level sludge drying machine in series respectively heat the sludge through solar heating systems.
For example, in the secondary sludge drying machine 14, the sludge is further dried and heated by secondary circulating hot air from the solar air collector 9 or the heat storage device 10. The temperature grade of the solar heat energy is higher, so the method is more suitable for drying and heating the sludge in the middle-high temperature section.
In daytime, secondary circulating hot air from a hot air outlet of the secondary sludge drying machine enters the second drying pipe 16 for drying, enters the solar air heat collector 9 under the action of the second circulating pump 18 to obtain heat, and returns to a hot air inlet of the secondary sludge drying machine. More specifically, in the daytime, when the solar energy resources are abundant, the second circulation pump 18 and the shut-off valve 22 are opened, the third circulation pump 19 is closed, the secondary circulating hot air absorbs heat from the solar air heat collector 9, the first flow regulating valve 20 and the second flow regulating valve 21 are regulated according to the solar irradiation intensity and the sludge mass flow rate, so as to regulate the flow of the secondary circulating hot air entering the heat storage device 10 and the secondary sludge drying machine 14, the secondary circulating hot air after releasing heat in the heat storage device 10 enters the solar air heat collector 9 again, and the hot air exiting the secondary sludge drying machine 14 needs to be dried by the second drying pipe 16 and then enters the solar air heat collector 9 again, so as to complete the circulation.
At night, the secondary circulating hot air from the hot air outlet of the secondary sludge drying machine enters the second drying pipe 16 for drying, enters the heat storage device 10 again under the action of the third circulating pump 19 to obtain heat, and returns to the hot air inlet of the secondary sludge drying machine. More specifically, when solar energy resources are insufficient at night and the like, the second circulating pump 18 and the shutoff valve 22 are closed, the third circulating pump 19 is opened, the secondary circulating hot air absorbs heat from the heat storage device 10 and then enters the secondary sludge drying machine 14 to dry sludge, and the hot air at the outlet of the secondary sludge drying machine 14 enters the second drying pipe 16 to be dried and then enters the heat storage device 10 again to absorb heat, so that the circulation is completed.
As an improved implementation manner, this embodiment further includes a tail gas disposal step:
the flue gas from the flue gas outlets of the absorption heat pump 3 and the air preheater 2 is gathered and then sequentially passes through the dust remover 4 and the flue gas desulfurization and denitrification device 5, and is discharged into the atmospheric environment from the chimney 7 under the action of the draught fan 6 after reaching the emission standard. The embodiment processes the flue gas discharged from the absorption heat pump 3 and the air preheater 2, and further avoids the condition that the discharged flue gas is directly discharged into the atmosphere.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.
Claims (13)
1. The utility model provides a cascade utilization system is synthesized to thermal power plant's flue gas-mud-solar energy which characterized in that includes:
the boiler (1) is used for providing heat energy for a thermal power plant; the boiler (1) is provided with a high-temperature flue gas outlet and a raw material inlet;
the air preheater (2) is communicated with the high-temperature flue gas exhaust port of the boiler (1) through a main flue and is used for preheating air by using the waste heat of the high-temperature flue gas exhausted by the boiler (1);
the absorption heat pump (3) is communicated with and arranged at the side part of the main flue through a bypass flue and is used for converting a small amount of high-grade high-temperature flue gas heat into a large amount of low-grade circulating hot air heat and cold water cold;
the solar heating system is used for collecting solar heat energy and converting the solar energy into heat energy;
the sludge drying system comprises at least two stages of sludge drying machines which are sequentially connected in series, wherein the sludge drying machines at all stages sequentially dry and transmit sludge; the primary sludge drying machine heats the sludge through the absorption heat pump (3), each secondary sludge drying machine heats the sludge through the solar heating system, and the secondary sludge drying machine at the tail part can input the dried sludge into the boiler (1) for incineration.
2. The heat-engine plant flue gas-sludge-solar energy comprehensive cascade utilization system according to claim 1, wherein the absorption heat pump (3) comprises:
the generator (33) is internally provided with a cavity shape and is provided with a flue gas pipe network communicated with the bypass flue;
the absorber (31) is arranged in a cavity shape and is provided with a first circulating hot air pipe network, and the first circulating hot air pipe network is communicated with a hot air outlet of the primary sludge drying machine; the inner cavity of the generator (33) is communicated with the inner cavity of the absorber (31) through a dilute absorption solution circulating system;
the condenser (34) is arranged in a cavity shape and is provided with a second circulating hot air pipe network communicated with the first circulating hot air pipe network, and the second circulating hot air pipe network is communicated with a hot air inlet of the primary sludge drying machine; a high-temperature steam outlet of the generator (33) is communicated with an inner cavity of the condenser (34);
the evaporator (36) is arranged in a cavity shape and is provided with a cold water pipe network for introducing cold water; a condensed water outlet of the condenser (34) is communicated with an inner cavity of the evaporator (36), and a low-temperature and low-pressure water vapor outlet of the evaporator (36) is communicated with an inner cavity of the absorber (31).
3. The heat-engine plant flue gas-sludge-solar energy comprehensive cascade utilization system according to claim 2, wherein the primary circulating hot air system comprises:
one end of the primary circulating hot air outlet pipe is communicated with a hot air outlet of the second circulating hot air pipe network, and the other end of the primary circulating hot air outlet pipe is communicated with the primary sludge drier;
one end of the primary circulating hot air inlet pipe is communicated with the primary sludge drier, and the other end of the primary circulating hot air inlet pipe is communicated with a hot air inlet of the first circulating hot air pipe network;
the first drying pipe (15) is arranged on the primary circulating hot air inlet pipe and is used for drying the primary circulating air output from the primary sludge drying machine;
and the first circulating pump (17) is arranged on the primary circulating hot air inlet pipe.
4. The comprehensive cascade utilization system of flue gas-sludge-solar energy of a thermal power plant according to claim 2, wherein a wet sludge conveying mechanism for inputting sludge is communicated with the primary sludge drying machine.
5. The comprehensive cascade utilization system of flue gas-sludge-solar energy of a thermal power plant according to claim 1, wherein the solar heating system comprises:
the secondary circulating hot air pipe is circularly and hermetically connected to the secondary sludge drying machine and is used for conveying secondary circulating hot air; a shutoff valve (22) and a first flow regulating valve (20) are arranged on the secondary circulating hot air pipe;
the solar air heat collector (9) is arranged on the secondary circulating hot air pipe and is used for collecting medium-high temperature solar heat energy and heating secondary circulating hot air;
the second circulating pump (18) is arranged on the secondary circulating hot air pipe;
and the second drying pipe (16) is arranged on the secondary circulating hot air pipe and is used for drying the secondary circulating hot air.
6. The comprehensive cascade utilization system of flue gas-sludge-solar energy of a thermal power plant according to claim 5, wherein the secondary circulating hot air pipes are connected in parallel and communicated with secondary circulating hot air branch pipes, and the secondary circulating hot air branch pipes are provided with:
the heat storage equipment (10) can store redundant heat when solar energy resources are rich and release heat when the solar energy resources are insufficient at night;
a third circulation pump (19);
and the second flow regulating valve (21) is used for regulating the amount of the secondary circulating hot air input to the heat storage device (10).
7. The comprehensive cascade utilization system of flue gas-sludge-solar energy of a thermal power plant as claimed in claim 6, wherein the interior of the heat storage device (10) is provided with a medium-temperature phase-change material.
8. The heat-engine plant flue gas-sludge-solar energy comprehensive cascade utilization system according to claim 2, characterized by further comprising:
and the tail gas treatment system is used for treating the tail gas exhausted from the air preheater (2) and the absorption heat pump (3).
9. The heat-engine plant flue gas-sludge-solar energy comprehensive cascade utilization system according to claim 8, wherein the tail gas treatment system comprises:
the dust remover (4) is communicated with the air outlet end of the air preheater (2) and the air outlet end of the flue gas pipe network and is used for removing dust from the flue gas;
the flue gas desulfurization and denitrification device (5) is communicated with the gas outlet end of the dust remover (4) and is used for desulfurization and denitrification of flue gas;
the exhaust pipeline is communicated with the gas outlet end of the flue gas desulfurization and denitrification device (5);
the induced draft fan (6) is arranged on the exhaust pipeline;
and the chimney (7) is communicated with the tail end of the exhaust pipeline and is used for exhausting tail gas.
10. A comprehensive cascade utilization method of flue gas-sludge-solar energy of a thermal power plant is characterized in that the method is carried out based on the comprehensive cascade utilization system of flue gas-sludge-solar energy of the thermal power plant as claimed in any one of claims 1 to 9, and comprises the following steps:
s1, high-temperature flue gas generated by a boiler (1) is divided into two parts: one part of high-temperature flue gas enters an air preheater (2) through a main flue to exchange heat with air, and the other part of high-temperature flue gas enters a generator (33) of an absorption heat pump (3) through a bypass flue;
s2, the absorption heat pump (3) takes high-temperature flue gas of a bypass flue as a high-temperature driving heat source, takes cold water as a low-temperature heat source, and heats primary circulating hot air by absorbing heat of the high-temperature flue gas and the cold water;
s3, the sludge sequentially enters sludge drying machines at all levels to be dried and heated step by step under the conveying of the wet sludge conveying mechanism, and is finally input into a boiler (1) to be mixed with coal and then combusted;
wherein the primary sludge drying machine heats the sludge through the absorption heat pump (3); and each secondary sludge drying machine heats the sludge through a solar heating system.
11. The comprehensive cascade utilization method of flue gas-sludge-solar energy of a thermal power plant according to claim 10, wherein in the step S3, the step of heating the sludge by the primary sludge drying machine through the absorption heat pump (3) comprises:
in the primary sludge drying machine, primary circulating hot air from a condenser (34) in an absorption heat pump (3) is used for drying and heating sludge; the hot air from the outlet of the primary sludge drier is dried by the first drying pipe (15) and then enters the absorber (31) of the absorption heat pump again to obtain heat.
12. The comprehensive cascade utilization method of flue gas-sludge-solar energy of a thermal power plant according to claim 10, wherein in the step S3, the step of heating the sludge by each secondary sludge drier through a solar heating system respectively comprises:
secondary circulating hot air from a hot air outlet of the secondary sludge drying machine enters a second drying pipe (16) for drying, enters a solar air heat collector (9) under the action of a second circulating pump (18) to obtain heat, and then returns to a hot air inlet of the secondary sludge drying machine;
or secondary circulating hot air from a hot air outlet of the secondary sludge drying machine enters a second drying pipe (16) for drying, enters the heat storage equipment (10) again under the action of a third circulating pump (19) to obtain heat, and returns to a hot air inlet of the secondary sludge drying machine.
13. The comprehensive cascade utilization method of flue gas-sludge-solar energy of a thermal power plant according to claim 10, characterized by further comprising a tail gas disposal step:
the flue gas coming out of the flue gas outlet of the absorption heat pump (3) and the air preheater (2) is converged and then sequentially passes through the dust remover (4) and the flue gas desulfurization and denitrification device (5), and is discharged into the atmospheric environment from the chimney (7) under the action of the draught fan (6) after reaching the emission standard.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211365471.3A CN115899716A (en) | 2022-11-02 | 2022-11-02 | Thermal power plant flue gas-sludge-solar energy comprehensive gradient utilization system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211365471.3A CN115899716A (en) | 2022-11-02 | 2022-11-02 | Thermal power plant flue gas-sludge-solar energy comprehensive gradient utilization system and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115899716A true CN115899716A (en) | 2023-04-04 |
Family
ID=86494253
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211365471.3A Pending CN115899716A (en) | 2022-11-02 | 2022-11-02 | Thermal power plant flue gas-sludge-solar energy comprehensive gradient utilization system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115899716A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117142742A (en) * | 2023-10-24 | 2023-12-01 | 国能龙源环保有限公司 | System and method for drying sludge by utilizing waste heat of coal-fired power plant |
-
2022
- 2022-11-02 CN CN202211365471.3A patent/CN115899716A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117142742A (en) * | 2023-10-24 | 2023-12-01 | 国能龙源环保有限公司 | System and method for drying sludge by utilizing waste heat of coal-fired power plant |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101858231B (en) | Energy supply system mainly through gas and steam combined cycle cogeneration | |
| CN110748899A (en) | Coal-fired coupled sludge drying incineration system and method considering waste heat utilization | |
| CN101906996A (en) | Cogeneration system by firing coil assisted by biomass and solar energy | |
| CN112430469A (en) | Greenhouse heat supply and carbon dioxide collecting system based on biomass pyrolysis technology | |
| CN115899716A (en) | Thermal power plant flue gas-sludge-solar energy comprehensive gradient utilization system and method | |
| CN208918610U (en) | Supercritical CO 2 and coal fired power plant decarburization integrate and the electricity generation system of UTILIZATION OF VESIDUAL HEAT IN | |
| CN211040991U (en) | Coal-fired coupling sludge drying and incinerating system considering waste heat utilization | |
| CN112833382A (en) | Multi-stage waste heat comprehensive utilization device and method for power plant | |
| CN111362551A (en) | Two-stage sludge drying and incinerating system of coal-fired power plant and operation method | |
| CN217127253U (en) | Sludge treatment system | |
| CN112520974B (en) | Coupling sludge low-temperature drying treatment system for garbage incineration plant | |
| CN212051067U (en) | Two-stage sludge drying and incinerating system of coal-fired power plant | |
| CN214745672U (en) | Multistage waste heat comprehensive utilization device of power plant | |
| CN204240391U (en) | Superheat steam drying powder process type coal generating system | |
| CN204240384U (en) | Superheat steam drying powder process type coal generating system | |
| CN210764950U (en) | Sludge drying equipment | |
| CN114477709A (en) | Heavy metal sludge carbonization system not prone to blockage | |
| CN112856449A (en) | Flue gas waste heat recovery system based on sludge blending burning power station | |
| CN108613507B (en) | Sludge treatment device with combined drying and incineration coupling | |
| CN208087552U (en) | A kind of cement sensible heat recovery system of biomass gasification burning | |
| CN111847835A (en) | Light and heat coal-fired coupled sludge drying system | |
| CN101837230A (en) | Device for reclaiming moisture in boiler flue gas of contact-type electric station | |
| CN201738958U (en) | Mixed electric generating system with renewable energy supporting coal | |
| CN108658417A (en) | A kind of coal unit collaboration desiccation municipal sludge system | |
| CN114623460B (en) | System for drying biomass by using flue gas waste heat |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |