CN111486469A - Coal-fired thermal power plant waste heat and water recovery system with heat storage function and method - Google Patents

Coal-fired thermal power plant waste heat and water recovery system with heat storage function and method Download PDF

Info

Publication number
CN111486469A
CN111486469A CN202010459407.6A CN202010459407A CN111486469A CN 111486469 A CN111486469 A CN 111486469A CN 202010459407 A CN202010459407 A CN 202010459407A CN 111486469 A CN111486469 A CN 111486469A
Authority
CN
China
Prior art keywords
heat
flue gas
heat exchange
coal
power plant
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
Application number
CN202010459407.6A
Other languages
Chinese (zh)
Inventor
张钧泰
张国柱
白玉勇
谷小兵
刘忠秋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Datang Environment Industry Group Co Ltd
Datang Beijing Energy Management Co Ltd
Original Assignee
Datang Environment Industry Group Co Ltd
Datang Beijing Energy Management Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Datang Environment Industry Group Co Ltd, Datang Beijing Energy Management Co Ltd filed Critical Datang Environment Industry Group Co Ltd
Priority to CN202010459407.6A priority Critical patent/CN111486469A/en
Publication of CN111486469A publication Critical patent/CN111486469A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23JREMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00Arrangements of devices for treating smoke or fumes
    • F23J15/06Arrangements of devices for treating smoke or fumes of coolers
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22STEAM GENERATION
    • F22DPREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
    • F22D1/00Feed-water heaters, i.e. economisers or like preheaters
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23LSUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
    • F23L15/00Heating of air supplied for combustion
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24DDOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
    • F24D15/00Other domestic- or space-heating systems
    • F24D15/02Other domestic- or space-heating systems consisting of self-contained heating units, e.g. storage heaters
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B15/00Sorption machines, plants or systems, operating continuously, e.g. absorption type
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B27/00Machines, plants or systems, using particular sources of energy
    • F25B27/02Machines, plants or systems, using particular sources of energy using waste heat, e.g. from internal-combustion engines
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A30/00Adapting or protecting infrastructure or their operation
    • Y02A30/27Relating to heating, ventilation or air conditioning [HVAC] technologies
    • Y02A30/274Relating to heating, ventilation or air conditioning [HVAC] technologies using waste energy, e.g. from internal combustion engine
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/62Absorption based systems
    • Y02B30/625Absorption based systems combined with heat or power generation [CHP], e.g. trigeneration
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00Combustion technologies with mitigation potential
    • Y02E20/34Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Abstract

The invention provides a waste heat and water recovery system with heat storage for a coal-fired thermal power plant, which comprises a boiler, an air preheater, a plurality of coolers, a dust remover, a desulfurizing tower, a flue gas condensing heat exchanger and a chimney which are sequentially arranged along the flow direction of flue gas; the multiple coolers are sequentially connected in series, the outlet temperatures of heat exchange media of the multiple coolers are sequentially reduced along the circulation direction of flue gas, and the multiple condensers correspond to unused heat utilization equipment; the heat exchange system is characterized by further comprising a thermocline heat storage tank and a heat supply network, wherein a hot water output end of the thermocline heat storage tank is communicated with the heat supply network, and a hot water input end of the thermocline heat storage tank is directly or indirectly communicated with a heat exchange medium pipeline of the flue gas condensation heat exchanger and a heat exchange medium pipeline of a part of coolers. The system realizes cascade utilization of energy, can simultaneously realize energy conservation, water recovery and thermoelectric decoupling, improves the efficiency of the unit waste heat and water recovery system, and simultaneously improves the flexibility of unit operation.

Description

Coal-fired thermal power plant waste heat and water recovery system with heat storage function and method
Technical Field
The invention relates to the technical field of waste heat and water recovery of coal-fired thermal power plants, in particular to a system and a method for recovering waste heat and water of a coal-fired thermal power plant with heat storage.
Background
Coal-fired power generation in China is still the main power generation body, the efficiency and the operation flexibility of a coal-fired power station are improved, and the problems of pollutant emission reduction and resource consumption reduction are long-term concerns of the coal-fired power station. The waste heat recovery of the exhaust smoke of the coal-fired power plant can reduce the heat loss of the exhaust smoke of the boiler, thereby improving the power generation efficiency of the coal-fired power plant. Meanwhile, due to the fact that heat supply in the north and steam are needed by part of enterprises, a cogeneration unit is indispensable.
Coal-fired power generation is still the main power generation body in China, and the problems of reducing pollutant emission and resource consumption and improving the efficiency and the operation flexibility of a power station are long-term concerns of the coal-fired power station. Cogeneration is one of the effective measures to reduce the energy consumption of coal-fired power stations. However, the cogeneration unit has a strong constraint relation of thermoelectric load coupling, so that the independent regulation capacity of the thermal load and the electric load is weak, and the new energy power generation is difficult to absorb, and the peak regulation capacity is poor. The heat and power decoupling can effectively improve the flexible operation level of the cogeneration unit, but the existing heat and power decoupling scheme mostly increases the energy consumption of the system. Therefore, the realization of flue gas water recovery and flue gas waste heat recovery of the coal-fired power plant is a key problem to be solved urgently in the electric power industry of China. The waste heat recovery of the exhaust smoke of the coal-fired power plant can reduce the heat loss of the exhaust smoke of the boiler, thereby improving the power generation efficiency of the coal-fired power plant. The main technology of the existing flue gas water recovery is a condensation method. The flue gas condensate water is recycled, so that the moisture in the flue gas can be recycled, but the steam is condensed to release a large amount of latent heat of vaporization in the water recycling process, the grade is low, and the latent heat of vaporization is difficult to use, so that the problems of the prior art are that a water recycling system and a waste heat recycling system are isolated, the investment is large, and the waste heat recycling is insufficient.
Disclosure of Invention
The invention aims to provide a coal-fired thermal power plant waste heat and water recovery system with heat storage, which can solve the problem of insufficient waste heat recovery;
the second purpose of the invention is to provide a method for recovering the waste heat and water of the coal-fired thermal power plant with heat storage, which adopts the system for recovering the waste heat and water of the coal-fired thermal power plant with heat storage.
The invention provides a waste heat and water recovery system with heat storage for a coal-fired thermal power plant, which comprises a boiler, an air preheater, a plurality of coolers, a dust remover, a desulfurizing tower, a flue gas condensing heat exchanger and a chimney which are sequentially arranged along the circulation direction of flue gas;
the multiple coolers are sequentially connected in series, the outlet temperatures of heat exchange media of the multiple coolers are sequentially reduced along the circulation direction of flue gas, and the multiple condensers correspond to unused heat utilization equipment;
the heat exchange system is characterized by further comprising a thermocline heat storage tank and a heat supply network, wherein a hot water output end of the thermocline heat storage tank is communicated with the heat supply network, and a hot water input end of the thermocline heat storage tank is directly or indirectly communicated with a heat exchange medium pipeline of the flue gas condensation heat exchanger and a heat exchange medium pipeline of a part of coolers.
Preferably, the plurality of coolers are respectively a flue gas high-temperature cooler, a flue gas medium-temperature cooler and a flue gas low-temperature cooler;
along the circulation direction of flue gas, the flue gas passageway of flue gas high temperature cooler, flue gas medium temperature cooler and flue gas low temperature cooler communicates in proper order.
Preferably, the system further comprises a turbine cooling heat recovery system, and a medium circulation heat exchange channel is formed between the heat exchange medium pipeline of the flue gas high-temperature cooler and the turbine cooling heat recovery system.
Preferably, the system also comprises a heat pump, a cooling water pipeline of the heat pump is communicated with a heat exchange medium pipeline of the flue gas condensation heat exchanger, and a medium circulation heat exchange channel is formed among a hot water pipeline of the heat pump, the heat exchange medium pipeline of the flue gas medium temperature cooler and a hot water input end of the thermocline heat storage tank.
Preferably, the system also comprises a flue gas reheater, wherein the flue gas reheater is arranged between the flue gas condensing heat exchanger and the chimney;
and a medium circulating heat exchange channel is formed between a hot water pipeline of the heat pump and a heat exchange medium pipeline of the flue gas reheater.
Preferably, the boiler also comprises a fan heater, wherein a flue gas channel of the fan heater is communicated with an air inlet of the boiler;
and a medium circulating heat exchange channel is formed between the heat exchange medium pipeline of the air heater and the heat exchange medium pipeline of the flue gas low-temperature cooler.
Preferably, the temperature of the outlet of the working medium side of the air heater is 65-75 ℃, and the air is heated to 70-90 ℃ in the air heater.
Preferably, the heat exchange medium of the flue gas high-temperature cooler, the flue gas medium-temperature cooler and the flue gas low-temperature cooler is water;
the water temperature at the outlet of the flue gas high-temperature cooler is 120-150 ℃;
the outlet water temperature of the flue gas medium temperature cooler is 100-120 ℃;
the outlet water temperature of the flue gas low-temperature cooler is 80-100 ℃.
Preferably, the temperature of the flue gas at the outlet of the flue gas condensation heat exchanger is 42-49 ℃; and the temperature of the flue gas at the outlet of the flue gas reheater is 57-64 ℃.
The method for recovering the waste heat and water of the coal-fired thermal power plant with the heat storage adopts the system for recovering the waste heat and water of the coal-fired thermal power plant with the heat storage, and comprises the following steps:
the method comprises the following steps that flue gas exhausted from a boiler sequentially passes through a plurality of coolers, heat exchange media in the coolers and flue gas flowing through the coolers are subjected to heat exchange and then output heat exchange media with different temperatures, and the heat exchange media are conveyed to different heat utilization equipment according to the difference of direct temperatures of heat exchange to utilize waste heat;
partial heat exchange medium is conveyed to the thermocline heat storage tank, when the heat recovered through the flue gas condensation heat exchanger and the partial cooler cannot meet the external heat supply requirement, the heat of the thermocline heat storage tank is fed into the heat supply network for heat supply, and when the heat recovered through the flue gas condensation heat exchanger and the partial cooler can meet the external heat supply requirement, the heat recovered by the heat pump has the thermocline heat storage tank.
Has the advantages that:
the system is provided with a plurality of coolers, and the plurality of coolers can recover heat in flue gas with different temperatures and convey the recovered heat to different heat utilization equipment. For example, the high-temperature boiler flue gas waste heat can be recycled to a turbine regenerative system to heat condensed water so as to reduce the coal consumption of power generation, the middle-temperature part of flue gas waste heat is used for further increasing the temperature of a high-temperature working medium at the outlet of the heat pump, and the low-temperature part of flue gas waste heat is used for preheating air; the flue gas at the outlet of the desulfurizing tower is subjected to water recovery through the condensing heat exchanger, and meanwhile, a large amount of low-level latent heat released due to liquefaction in the water recovery process is heated and stored in the thermocline heat storage tank to supply heat load required by a heat supply network. Namely, the cascade utilization of energy is realized, energy conservation, water recovery and thermoelectric decoupling can be realized simultaneously, the efficiency of the unit waste heat and water recovery system is improved, and the flexibility of unit operation is improved simultaneously.
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 waste heat and water recovery system of a coal-fired thermal power plant with heat storage according to an embodiment of the present invention.
Description of reference numerals:
1: a boiler; 2: an air preheater; 3: a flue gas high-temperature cooler; 4: a turbine cooling regenerative system; 5: a flue gas medium temperature cooler; 6: a flue gas cryocooler; 7: a dust remover; 8: a desulfurizing tower; 9: a flue gas condensing heat exchanger; 10: a flue gas reheater; 11: a heat pump; 12: a warm air blower; 13: a thermocline heat storage tank; 14: a heat supply network; 15: and (4) a chimney.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, 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 is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and 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 considered as limiting the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. Furthermore, the terms "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; 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.
As shown in fig. 1, in the present embodiment, a waste heat and water recovery system with heat storage for a coal-fired thermal power plant is provided, and the system includes a boiler 1, an air preheater 2, a plurality of coolers, a dust remover 7, a desulfurizing tower 8, a flue gas condensing heat exchanger 9 and a chimney 15, which are sequentially arranged along a flue gas circulation direction.
The plurality of coolers are sequentially connected in series, the outlet temperature of the heat exchange medium of the plurality of coolers is sequentially reduced along the smoke flowing direction, and the plurality of condensers correspond to the heat utilization equipment which is not used.
The flue gas heat exchanger further comprises an inclined temperature layer heat storage tank 13 and a heat supply network 14, a hot water output end of the inclined temperature layer heat storage tank 13 is communicated with the heat supply network 14, and a hot water input end of the inclined temperature layer heat storage tank 13 is directly or indirectly communicated with a heat exchange medium pipeline of the flue gas condensation heat exchanger 6 and a heat exchange medium pipeline of a part of coolers.
The system is provided with a plurality of coolers, and the plurality of coolers can recover heat in flue gas with different temperatures and convey the recovered heat to different heat utilization equipment. For example, the high-temperature boiler flue gas waste heat can be recycled to a turbine regenerative system to heat condensed water so as to reduce the coal consumption of power generation, the middle-temperature part of flue gas waste heat is used for further increasing the temperature of a high-temperature working medium at the outlet of the heat pump, and the low-temperature part of flue gas waste heat is used for preheating air; the flue gas at the outlet of the desulfurizing tower is subjected to water recovery through the condensing heat exchanger, and meanwhile, a large amount of low-level latent heat released due to liquefaction in the water recovery process is heated and stored in the thermocline heat storage tank to supply heat load required by a heat supply network. Namely, the cascade utilization of energy is realized, energy conservation, water recovery and thermoelectric decoupling can be realized simultaneously, the efficiency of the unit waste heat and water recovery system is improved, and the flexibility of unit operation is improved simultaneously.
Specifically, the multiple coolers are a flue gas high-temperature cooler 3, a flue gas medium-temperature cooler 4 and a flue gas low-temperature cooler 6 respectively.
Along the flowing direction of the flue gas, the flue gas channels of the flue gas high-temperature cooler 3, the flue gas medium-temperature cooler 4 and the flue gas low-temperature cooler 6 are communicated in sequence.
The waste heat and water recovery system of the coal-fired thermal power plant with the heat storage function further comprises a turbine cooling heat recovery system 4, and a medium circulating heat exchange channel is formed between a heat exchange medium pipeline of the flue gas high-temperature cooler 3 and the turbine cooling heat recovery system 4.
The flue gas high-temperature cooler 3 is a heat exchanger arranged in a countercurrent mode, and the outlet design water temperature is 120-150 ℃.
Through medium circulation between the flue gas high-temperature cooler 3 and the turbine cooling regenerative system 4, the high-temperature boiler flue gas waste heat can be recycled to the turbine regenerative system to heat condensed water so as to reduce the coal consumption of power generation.
The waste heat and water recovery system with heat storage for the coal-fired thermal power plant further comprises a heat pump 11 and a flue gas reheater 10, a cooling water pipeline of the heat pump 11 is communicated with a heat exchange medium pipeline of a flue gas condensing heat exchanger 9, and a medium circulation heat exchange channel is formed among a hot water pipeline of the heat pump 11, a heat exchange medium pipeline of a flue gas medium temperature cooler 5 and a hot water input end of an inclined temperature layer heat storage tank 13.
The flue gas reheater 10 is arranged between the flue gas condensing heat exchanger 9 and the chimney 15, and a medium circulating heat exchange channel is formed between a hot water pipeline of the heat pump 11 and a heat exchange medium pipeline of the flue gas reheater 10.
The circulation process of heat among the flue gas intermediate temperature cooler 5, the heat pump 11 and the flue gas reheater 10 is as follows: the flue gas at the outlet of the desulfurizing tower 8 is subjected to water recovery through the flue gas condensation heat exchanger 9, and meanwhile, in the water recovery process, a large amount of low-level latent heat is released due to liquefaction, the energy level of the part of heat is improved by using the heat pump 11, one part of heat is used for reheating the flue gas to prevent low-temperature corrosion of the flue gas, and the other part of heat is continuously heated in the flue gas middle-temperature cooler 5 and stored in the inclined temperature layer heat storage tank 13 to supply heat load required by the heat supply network 14. The temperature of the high-temperature working medium at the outlet of the heat pump is further raised through the middle-temperature part of the flue gas waste heat, and the low-temperature part of the flue gas waste heat is used for preheating air.
The design water temperature of the outlet of the flue gas medium temperature cooler 5 is 100-120 ℃, the temperature of the flue gas at the outlet of the flue gas condensing heat exchanger 9 is 42-49 ℃, and the temperature of the flue gas at the outlet of the flue gas reheater 10 is 57-64 ℃.
The waste heat and water recovery system of the coal-fired thermal power plant with the heat storage function further comprises a fan heater 12, and a flue gas channel of the fan heater 12 is communicated with an air inlet of the boiler 1.
A medium circulating heat exchange channel is formed between the heat exchange medium pipeline of the air heater 12 and the heat exchange medium pipeline of the flue gas low-temperature cooler.
The temperature of the outlet of the working medium side of the air heater 12 is 65-75 ℃, and the air is heated to 70-90 ℃ in the air heater 12.
Through the circulation of the heat exchange medium between the air heater 12 and the flue gas low-temperature cooler 6, the flue gas waste heat of the low-temperature part is used for preheating air.
In this embodiment, there is also provided a method for recovering waste heat and water of a coal-fired thermal power plant with heat storage, which adopts the above-mentioned system for recovering waste heat and water of a coal-fired thermal power plant with heat storage, and includes the following steps:
the method comprises the following steps that flue gas exhausted from a boiler sequentially passes through a plurality of coolers, heat exchange media in the coolers and flue gas flowing through the coolers are subjected to heat exchange and then output heat exchange media with different temperatures, and the heat exchange media are conveyed to different heat utilization equipment according to the difference of direct temperatures of heat exchange to utilize waste heat;
partial heat exchange medium is conveyed to the thermocline heat storage tank, when the heat recovered through the flue gas condensation heat exchanger and the partial cooler cannot meet the external heat supply requirement, the heat of the thermocline heat storage tank is fed into the heat supply network for heat supply, and when the heat recovered through the flue gas condensation heat exchanger and the partial cooler can meet the external heat supply requirement, the heat recovered by the heat pump has the thermocline heat storage tank.
Specifically, the specific implementation manner of the method for recovering the waste heat and water of the coal-fired thermal power plant with heat storage is as follows: the boiler exhaust smoke of the boiler 1 firstly enters a smoke high-temperature cooler 3, the smoke is cooled by water led out from a turbine cooling regenerative system 4, then the flue gas enters a flue gas medium temperature cooler 5 and a flue gas low temperature cooler 6 in sequence to cool the flue gas to 90-100 ℃, the waste heat recovered by the flue gas medium temperature cooler 5 is used for heating working medium at the outlet of a heat pump 11, the heat recovered by the flue gas low temperature cooler 6 is used for preheating air, then, the flue gas is dedusted by a deduster 7, desulfurized in a desulfurizing tower 8 and then enters a flue gas condensing heat exchanger 9, moisture in the flue gas is condensed and recovered, heat is absorbed from the flue gas condensing heat exchanger 9 by a heat pump 11, a part of hot water working medium heated by the heat pump 11 is shunted and enters a flue gas reheater 10 for reheating the flue gas to prevent low-temperature corrosion, the cooled working medium returns to a low-temperature side inlet of the heat pump 11, and the rest part of the working medium enters a flue gas middle-temperature cooler 5 to continuously absorb heat and raise the temperature to 100-120 ℃; when the unit can not satisfy the external heat supply demand, the heat of the thermocline heat storage tank 13 is sent into the heat supply network for heat supply, and when the unit can satisfy the external heat supply demand, the heat recovered by the heat pump 11 exists in the thermocline heat storage tank 13, so that the thermoelectric decoupling operation is realized.
In summary, the system and the method for recovering waste heat and water of the coal-fired thermal power plant with heat storage provided by the embodiment have the following effects:
(1) the waste heat of the boiler exhaust gas and the water are simultaneously recovered, and the energy-saving potential of the system reaches 2.3g/kWh to 3.8 g/kWh.
(2) The heat pump is utilized to improve the waste heat quality, and meanwhile, the heat supply load difference between the heat supply load of the heat supply network and the heat load required by the heat supply network is provided by utilizing the regulating system of the thermocline heat storage tank, so that the sufficient heat supply load of the heat supply network is ensured, and the thermoelectric decoupling is realized.
(3) Flue gas is reheated by using working medium at the outlet of the heat pump, so that corrosion to a chimney caused by excessively low temperature after delayed condensation is prevented.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A coal-fired thermal power plant waste heat and water recovery system with heat storage is characterized by comprising a boiler, an air preheater, a plurality of coolers, a dust remover, a desulfurizing tower, a flue gas condensing heat exchanger and a chimney which are sequentially arranged along the flue gas circulation direction;
the multiple coolers are sequentially connected in series, the outlet temperatures of heat exchange media of the multiple coolers are sequentially reduced along the circulation direction of flue gas, and the multiple condensers correspond to unused heat utilization equipment;
the heat exchange system is characterized by further comprising a thermocline heat storage tank and a heat supply network, wherein a hot water output end of the thermocline heat storage tank is communicated with the heat supply network, and a hot water input end of the thermocline heat storage tank is directly or indirectly communicated with a heat exchange medium pipeline of the flue gas condensation heat exchanger and a heat exchange medium pipeline of a part of coolers.
2. The heat-storing coal-fired thermal power plant waste heat and water recovery system according to claim 1, wherein the plurality of coolers are a flue gas high temperature cooler, a flue gas medium temperature cooler and a flue gas low temperature cooler, respectively;
along the circulation direction of flue gas, the flue gas passageway of flue gas high temperature cooler, flue gas medium temperature cooler and flue gas low temperature cooler communicates in proper order.
3. The heat and water recovery system of the coal-fired thermal power plant with heat storage of claim 2, further comprising a turbine cooling heat recovery system, wherein a medium circulation heat exchange channel is formed between the heat exchange medium pipeline of the flue gas high temperature cooler and the turbine cooling heat recovery system.
4. The system for recovering the waste heat and water of the coal-fired thermal power plant with the heat storage function according to claim 2, further comprising a heat pump, wherein a cooling water pipeline of the heat pump is communicated with a heat exchange medium pipeline of the flue gas condensation heat exchanger, and a medium circulation heat exchange channel is formed among a hot water pipeline of the heat pump, the heat exchange medium pipeline of the flue gas moderate temperature cooler and a hot water input end of the thermocline heat storage tank.
5. The heat-storing coal-fired thermal power plant waste heat and water recovery system according to claim 4, further comprising a flue gas reheater disposed between the flue gas condensing heat exchanger and the chimney;
and a medium circulating heat exchange channel is formed between a hot water pipeline of the heat pump and a heat exchange medium pipeline of the flue gas reheater.
6. The heat-storing coal-fired thermal power plant waste heat and water recovery system according to claim 2, further comprising a fan heater, wherein a flue gas channel of the fan heater is communicated with an air inlet of the boiler;
and a medium circulating heat exchange channel is formed between the heat exchange medium pipeline of the air heater and the heat exchange medium pipeline of the flue gas low-temperature cooler.
7. The heat-storing coal-fired thermal power plant waste heat and water recovery system according to claim 6, wherein the outlet temperature of the working medium side of the air heater is 65-75 ℃, and the air is heated to 70-90 ℃ in the air heater.
8. The heat-storing coal-fired thermal power plant waste heat and water recovery system according to claim 2, wherein the heat exchange medium of the flue gas high-temperature cooler, the flue gas medium-temperature cooler and the flue gas low-temperature cooler is water;
the water temperature at the outlet of the flue gas high-temperature cooler is 120-150 ℃;
the outlet water temperature of the flue gas medium temperature cooler is 100-120 ℃;
the outlet water temperature of the flue gas low-temperature cooler is 80-100 ℃.
9. The heat-storage coal-fired thermal power plant waste heat and water recovery system according to claim 5, wherein the temperature of the flue gas at the outlet of the flue gas condensing heat exchanger is 42-49 ℃; and the temperature of the flue gas at the outlet of the flue gas reheater is 57-64 ℃.
10. A method for recovering waste heat and water of a coal-fired thermal power plant with heat storage, which is characterized in that the method adopts the system for recovering waste heat and water of the coal-fired thermal power plant with heat storage according to any one of claims 1 to 9, and comprises the following steps:
the method comprises the following steps that flue gas exhausted from a boiler sequentially passes through a plurality of coolers, heat exchange media in the coolers and flue gas flowing through the coolers are subjected to heat exchange and then output heat exchange media with different temperatures, and the heat exchange media are conveyed to different heat utilization equipment according to the difference of direct temperatures of heat exchange to utilize waste heat;
partial heat exchange medium is conveyed to the thermocline heat storage tank, when the heat recovered through the flue gas condensation heat exchanger and the partial cooler cannot meet the external heat supply requirement, the heat of the thermocline heat storage tank is fed into the heat supply network for heat supply, and when the heat recovered through the flue gas condensation heat exchanger and the partial cooler can meet the external heat supply requirement, the heat recovered by the heat pump has the thermocline heat storage tank.
CN202010459407.6A 2020-05-27 2020-05-27 Coal-fired thermal power plant waste heat and water recovery system with heat storage function and method Pending CN111486469A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010459407.6A CN111486469A (en) 2020-05-27 2020-05-27 Coal-fired thermal power plant waste heat and water recovery system with heat storage function and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010459407.6A CN111486469A (en) 2020-05-27 2020-05-27 Coal-fired thermal power plant waste heat and water recovery system with heat storage function and method

Publications (1)

Publication Number Publication Date
CN111486469A true CN111486469A (en) 2020-08-04

Family

ID=71792400

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010459407.6A Pending CN111486469A (en) 2020-05-27 2020-05-27 Coal-fired thermal power plant waste heat and water recovery system with heat storage function and method

Country Status (1)

Country Link
CN (1) CN111486469A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112283694A (en) * 2020-10-26 2021-01-29 西安交通大学 Low-temperature flue gas water recovery and waste heat utilization coupling system of coal-fired power plant and operation method
CN114413311A (en) * 2022-01-20 2022-04-29 大唐环境产业集团股份有限公司 Cold-end waste heat supply system of coal-fired unit of coupling thermocline heat storage tank and operation method
CN114440292A (en) * 2021-12-11 2022-05-06 华能(浙江)能源开发有限公司长兴分公司 System and method for carrying out mobile heat storage by using flue gas of boiler of power station
CN114526158A (en) * 2022-01-26 2022-05-24 哈尔滨工业大学(深圳) Energy and substance conversion system and method based on carbon dioxide hydrogenation

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112283694A (en) * 2020-10-26 2021-01-29 西安交通大学 Low-temperature flue gas water recovery and waste heat utilization coupling system of coal-fired power plant and operation method
CN112283694B (en) * 2020-10-26 2021-07-09 西安交通大学 Low-temperature flue gas water recovery and waste heat utilization coupling system of coal-fired power plant and operation method
CN114440292A (en) * 2021-12-11 2022-05-06 华能(浙江)能源开发有限公司长兴分公司 System and method for carrying out mobile heat storage by using flue gas of boiler of power station
CN114413311A (en) * 2022-01-20 2022-04-29 大唐环境产业集团股份有限公司 Cold-end waste heat supply system of coal-fired unit of coupling thermocline heat storage tank and operation method
CN114526158A (en) * 2022-01-26 2022-05-24 哈尔滨工业大学(深圳) Energy and substance conversion system and method based on carbon dioxide hydrogenation
CN114526158B (en) * 2022-01-26 2023-04-25 哈尔滨工业大学(深圳) Energy and substance conversion system and method based on carbon dioxide hydrogenation

Similar Documents

Publication Publication Date Title
CN111486469A (en) Coal-fired thermal power plant waste heat and water recovery system with heat storage function and method
CN101900347B (en) System for high-grade recycling waste heat of smoke discharged from boiler of power station
CN111486468A (en) Coal-fired power plant waste heat recovery system and method
CN102454980B (en) Method for recycling flue gas waste heat of thermal power plant boiler
CN105889897B (en) A kind of thermal power plant residual heat integrative recycling system and method
CN102401393B (en) Exhaust waste heat recycling system of power plant boiler
CN103604249A (en) Energy tower absorption type hot and cold water unit
CN212408715U (en) Waste heat recovery system of coal-fired power plant
CN104235826A (en) Boiler flue gas waste heat recycling system
CN202791972U (en) Boiler tail flue gas waste heat utilization system
CN205332168U (en) Waste heat comprehensive recovery utilization system of thermal power factory
CN212930057U (en) Coal-fired thermal power plant waste heat and water recovery system with heat storage function
CN106322427A (en) Deslagging waste heat utilization system and deslagging waste heat utilization method for circulating fluidized bed boiler
CN201779684U (en) High-grade recycling system for exhaust heat of power station boiler
CN105402761A (en) Deep coupling utilization system for turbine steam exhaust waste heat and boiler flue gas waste heat
CN110986031B (en) System for avoiding water vapor condensation in gas boiler flue gas recirculation pipeline
CN203036658U (en) Boiler flue gas waste heat multipurpose utilization system
CN209588088U (en) A kind of thermal power plant burning high sulfur coal smoke waste heat utilization system
CN203489244U (en) Boiler smoke waste-heat applicable system
CN203671637U (en) Low-low temperature flue gas waste heat recovery system
CN110857843A (en) Coke oven waste heat Stirling power generation system
CN104832945A (en) Flue gas waste heat utilization system
CN210014388U (en) Deep recycling cascade utilization system for low-temperature flue gas waste heat of coal-fired unit
CN201819198U (en) High and low pressure combined-type economizer
CN104235827A (en) Boiler smoke waste heat utilization system

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