Desulfurization slurry flash evaporation waste heat recovery system for non-condensable gas desulfurization vacuumizing
Through the combination of the non-condensation gas desulfurization vacuum tank and the micro-pressure differential vacuum device, the deep heat recovery problem in the existing flue gas waste heat recovery system has been solved, and the significant reduction in flue gas temperature and significant increase in waste heat is achieved, which has improved the economic benefits and flexibility of the power plant.
Patent Information
- Application Number
- CN202422408817.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-09-30
AI Technical Summary
The existing flue gas waste heat recovery technology cannot achieve deep heat recovery, the flue gas temperature is difficult to reduce to 30℃, and the SO2 and other components in the non-condensed gas escape, resulting in complex equipment and high operating costs, which affects the economy of the power plant.
The desulfurization vacuum tank of non-condensation gas is used for secondary desulfurization, combined with a micro-pressure differential vacuum device and secondary flash evaporation and staging heat exchange, the SO2 component in the non-condensation gas is reduced through chemical or physical methods, and high vacuum operation is achieved, and the outlet temperature of the desulfurization slurry and the flue gas temperature are reduced.
Significantly reduce the total amount of non-condensed gas, increase the vacuum level, realize deep waste heat recovery of flue gas, reduce driving steam demand, improve the flexibility of the cogeneration system, and reduce water resource consumption.
Smart Images
Figure CN223050058U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a desulfurized slurry flash heat recovery system for vacuum extraction of non-condensable gas desulfurization, belonging to the technical field of waste heat heating of coal-fired boilers. Background Technique
[0002] During the heat production process of boilers, a large amount of high-temperature flue gas is discharged. Recycling the waste heat of the flue gas can not only reduce the heat loss of the boiler, but also reduce the fuel consumption and pollutant emissions such as greenhouse gases, and improve the thermal efficiency of the boiler. Therefore, the development of flue gas waste heat recovery technology is an important way to assist in the realization of the "dual carbon" strategic goal. In recent years, in the method of using an absorption heat pump for flue gas waste heat recovery, there has emerged a method of taking heat by desulfurized slurry flashing + absorption heat pump, that is, abandoning the flue gas waste heat exchanger, but taking the heat in the flue gas from the desulfurized slurry through a flash tank, sending the flash steam into the heat pump for waste heat recovery, heating the return water of the heat network or other process water, and returning the concentrated liquid to the desulfurized circulating water. Its advantages are: there is no need to transform the flue gas system, reducing the on-site implementation difficulty; the quality of the condensate water is good, which is convenient for recycling. However, the disadvantages are also very obvious: the flue gas temperature can usually only be reduced to 42 - 45°C, recovering about half of the flue gas waste heat, which does not belong to deep heat recovery and can only be regarded as a half-finished project. There is still a large amount of flue gas waste heat escaping from the flue gas, and secondary transformation is still required in the future to achieve deep heat recovery. The cost calculated for the unit waste heat recovery amount is relatively high, and the investment payback period is long. The fundamental reasons why it cannot reduce the flue gas temperature to the 30°C level and achieve deep heat recovery are as follows: First, the desulfurized slurry flashing complete set of equipment is a vacuum equipment, its system integration is relatively complex, the guarantee requirements are high, and the lower the flash steam temperature, the larger the specific volume, the larger the equipment volume, and the higher the cost; Second, a relatively large amount of non-condensable gases such as SO2 will escape during the desulfurized slurry flashing process. The flash steam is sent into the absorption heat pump, and it is difficult to evacuate during the condensation and heat release process in the horizontal evaporator of the heat pump. The absolute pressure during actual operation can only be maintained at about 7 - 8 kPa. It is very difficult to further improve the vacuum degree with the existing equipment and conditions, and it cannot further improve the vacuum degree like a normal condenser. Therefore, the saturation temperature of the flash steam can only be reduced to the 38 - 40°C level, resulting in the flue gas temperature can only be reduced to the 40 - 45°C level; Third, this technical method still belongs to the heat pump method in essence, only the heat extraction device is different. It still requires a large amount of driving steam, with high operating costs, deteriorating the thermal power flexibility adjustment problem of the power plant, and even sometimes seriously affecting the technical and economic benefits of the power plant. Content of the Utility Model
[0003] The purpose and task of the present utility model are, in view of the respective inherent technical limitations of the above-mentioned various flue gas waste heat recovery systems and their impacts on the economy of power plants, to significantly reduce the total amount of non-condensable gas by substantially reducing components such as SO2 in the non-condensable gas through chemical or physical anti-corrosion, so as to achieve high-vacuum operation, effectively reduce the outlet temperature of the desulfurization slurry, reduce the flue gas temperature at the outlet of the desulfurization tower, and realize deep waste heat recovery of the flue gas.
[0004] The specific description of the present utility model is: A desulfurized slurry flash evaporation waste heat recovery system for non-condensable gas desulfurization and vacuum extraction, which consists of an original desulfurization tower system and a desulfurized slurry flash evaporation heating and vacuum control subsystem. The original desulfurization tower system includes an original desulfurization tower 1, an original flue gas inlet pipe 2, and an original slurry pump 3. It is characterized in that the desulfurized slurry flash evaporation heating and vacuum control subsystem includes a high-vacuum flash evaporation tank 31, an absorption heat pump 36, a non-condensable gas desulfurization vacuum tank 39, a vacuum pump 18, a micro-pressure difference vacuum extraction device 38, and connecting pipelines and components. Among them, the slurry inlet of the high-vacuum flash evaporation tank 31 is connected to the waste heat slurry outlet of the bottom desulfurized slurry pool of the original desulfurization tower 1 through a waste heat slurry pump 10, and the outlet of the final-stage concentrated slurry of the high-vacuum flash evaporation tank 31 is connected to the inlet of the original slurry pump 3 or the desulfurized slurry pool; the flash steam outlet of the high-vacuum flash evaporation tank 31 is connected to the heat source inlet of the evaporator 36c inside the absorption heat pump 36 through a final-stage connecting pipe 35, and the heat source outlet of the evaporator 36c is connected to the inlet of the final-stage condensate pump 37; inside the absorption heat pump 36, there is also a generator 36b and an absorber condenser assembly 36a that communicate with the driving steam; the low-temperature water inlet of the absorber condenser assembly 36a communicates with the water supply pipe of the return water H1 from the heat network, and the low-temperature water outlet of the absorber condenser assembly 36a communicates with the drain pipe of the return water H2 of the heat network; the outlet of the non-condensable gas S2 containing more SO2 on the heat source outlet side of the evaporator 36c is connected to the non-condensable gas inlet of the non-condensable gas desulfurization vacuum tank 39. Inside the non-condensable gas desulfurization vacuum tank 39, there is also an alkali liquid spraying device 39a and a waterproof non-condensable gas suction device 39b. Below the lower liquid level and outside the tank body, there is also a hot well liquid level measurement and control component 39c. Among them, the lower part of the alkali liquid spraying device 39a is the area of the non-condensable gas S2 containing more SO2, and the upper part is the area of the non-condensable gas S1 containing less SO2; the outlet of the final-stage condensate pump 37 communicates with the outlet pipe of the final-stage external discharged condensate water W2 through a mixing water regulating valve 39d. The outlet of the final-stage condensate pump 37 is also connected to the outlet of the alkali addition pump 30 and the inlet of the alkali liquid spraying device 39a. The inlet of the alkali addition pump 30 communicates with the feed pipe of the sodium hydroxide solution Na; the bottom water outlet of the non-condensable gas desulfurization vacuum tank 39 is connected to the inlet of the final-stage condensate pump 37; the outlet of the waterproof non-condensable gas suction device 39b is connected to the air inlet of the micro-pressure difference vacuum extraction device 38, the exhaust outlet of the micro-pressure difference vacuum extraction device 38 is connected to the inlet of the vacuum pump 18, and the exhaust outlet of the vacuum pump 18 communicates with the original flue gas inlet pipe 2 of the original desulfurization tower 1; the upstream of the original flue gas inlet pipe 2 is the inlet of the original flue gas Y1 from the boiler outlet, the downstream is the flue gas inlet of the original desulfurization tower 1, the top of the original desulfurization tower 1 is the outlet of the clean flue gas Y2, and the sewage outlet of the bottom desulfurized slurry pool of the original desulfurization tower 1 communicates with the drain pipe of the desulfurized wastewater P.
[0005] When the temperature of the returning hot water H1 of the heat network is lower than the difference between the temperature of the desulfurized slurry at the outlet of the waste heat slurry pump 10 minus 10°C, a preflash tank 21 and a preheater 26 are also provided in the desulfurized slurry flash heating and vacuum control subsystem. At this time, the slurry inlet of the preflash tank 21 is connected to the waste heat slurry outlet of the bottom desulfurized slurry tank of the original desulfurization tower 1 through the waste heat slurry pump 10, and the slurry outlet of the preflash tank 21 is connected to the slurry inlet of the high-vacuum flash tank 31; the flash steam outlet of the preflash tank 21 is connected to the steam inlet of the preheater 26 through a preconnection pipe 25, the condensate outlet of the preheater 26 is connected to the inlet of the precondensate pump 27, and the outlet of the precondensate pump 27 communicates with the outlet pipe of the pre-outlet condensate water W1; the low-temperature water inlet of the preheater 26 communicates with the inlet pipe of the returning hot water H1 of the heat network, and the low-temperature water outlet of the preheater 26 is connected to the low-temperature water inlet of the absorber condenser assembly 36a of the absorption heat pump 36; the outlet of the non-condensable gas S on the liquid surface of the bottom hot well condensate of the preheater 26 is connected to the inlet of the vacuum pump 18; the condensate outlet of the non-condensable gas desulfurization vacuum tank 39 is connected to the inlet of the desulfurization tank drain pump 39e, and the outlet of the desulfurization tank drain pump 39e communicates with the outlet pipe of the final-stage outlet condensate water W2.
[0006] The preheater 26 adopts a vertical tube heat exchange structure or a horizontal tube heat exchange structure. When the vertical tube heat exchange structure is adopted, a condensate hot well is provided at the bottom, and a non-condensable gas discharge port is provided above the liquid surface of the hot well; when the horizontal tube heat exchange structure is adopted, a non-condensable gas discharge port is provided at the upper part of one end of the condensate outlet side.
[0007] The micro-pressure difference vacuum pumping device 38 adopts one or more roots compressors or negative pressure ejectors.
[0008] The vacuum pump 18 adopts a water ring vacuum pump, a water jet air ejector or a roots vacuum pump structure.
[0009] The outlet pipes of the pre-outlet condensate water W1 and the final-stage outlet condensate water W2 are respectively connected to the desulfurization makeup water B and the makeup water inlet pipe of the returning hot water H1 of the heat network.
[0010] The innovation points and beneficial effects of the present utility model are as follows.
[0011] (1) The non-condensable gas is secondarily desulfurized by the non-condensable gas desulfurization vacuum tank 39 to greatly reduce the SO2 and other components that can be absorbed or adsorbed therein, thereby significantly reducing the total amount of non-condensable gas, realizing high-vacuum operation, effectively reducing the outlet temperature of the desulfurized slurry and the outlet flue gas temperature of the desulfurization tower, realizing deep waste heat recovery of the flue gas, and the waste heat recovery amount can be increased by 50% or even more than 100% compared with the current conventional desulfurized slurry flash method.
[0012] (2) The secondary flash evaporation and staged heat exchange method can be adopted. Among them, for the pre-flash evaporation, a shell-and-tube heat exchanger is used to directly heat the return water of the heat network at a relatively low temperature, and the outlet water is then sent to an absorption heat pump for secondary heating, which can greatly compress the capacity and cost of the absorption heat pump. For the conventional desulfurization slurry flash evaporation + absorption heat pump scheme, the ratio of the recovered waste heat to the driving steam is only about 0.7, while this patent can increase it to about 1.4 - 5.0, greatly reducing the demand for driving steam and improving the flexibility of the adjustment of the cogeneration system of the whole plant.
[0013] (3) The preheater 26 adopts a vertical tube bundle heat exchange structure. Although a large amount of SO2 and other substances are contained in the non-condensable gas, a large amount of non-condensable gas can still be extracted by the vacuum pump 18 and the pressure of the flash tank can be effectively reduced, thereby effectively reducing the flue gas temperature.
[0014] (4) The use of a micro-pressure difference vacuum extraction device 38 can effectively discharge the non-condensable gas on the condensate side of the flash steam in the evaporator of the absorption heat pump, creating a higher vacuum degree for the high-vacuum flash tank, thereby greatly reducing the outlet temperature of the desulfurization slurry and the outlet temperature of the flue gas, and achieving deep heat recovery.
[0015] (5) The condensate of the flash steam can also be used as makeup water for the return water of the heat network, which helps to greatly reduce the water production volume and cost of softened water; at the same time, the comprehensive recovery and utilization of the condensate also correspondingly greatly reduces the consumption of water resources.
[0016] (6) This solution and system can be widely applied to the flue gas waste heat recovery and heating system of thermal power plants and boiler houses, promoting the realization of the comprehensive technical and economic benefits of energy conservation and environmental protection integration. Brief Description of the Drawings
[0017] Figure 1 is a schematic diagram of the system of Specific Embodiment 1 of the present utility model; Figure 2 is a schematic diagram of the system of Specific Embodiment 2 of the present utility model.
[0018] Figure 1 and 2 The numbers and names of each component in
[0019] Original desulfurization tower 1, original flue gas inlet pipe 2, original slurry pump 3, waste heat slurry pump 10, vacuum pump 18, pre - flash tank 21, pre - connecting pipe 25, pre - heater 26, pre - condensate pump 27, caustic soda pump 30, high - vacuum flash tank 31, final - stage connecting pipe 35, absorption heat pump 36, absorber condenser assembly 36a, generator 36b, evaporator 36c, final - stage condensate pump 37, micro - differential pressure vacuum extraction device 38, non - condensable gas desulfurization vacuum tank 39, caustic liquor spraying device 39a, waterproof non - condensable gas suction device 39b, hot well liquid level measurement and control assembly 39c, mixed water regulating valve 39d, desulfurization tank drain pump 39e, desulfurization make - up water B, return water of heat supply network H1, return water drainage of heat supply network H2, desulfurization wastewater P, pre - non - condensable gas S, less - SO2 non - condensable gas S1, more - SO2 non - condensable gas S2, pre - discharged condensate water W1, final - stage discharged condensate water W2, original flue gas Y1, clean flue gas Y2, sodium hydroxide solution Na. Detailed implementation manners
[0020] Figure 1 It is a system schematic diagram of specific embodiment 1 of the present utility model; Figure 2 It is a system schematic diagram of specific embodiment 2 of the present utility model.
[0021] The specific embodiments of the present utility model are as follows.
[0022] Specific description of Embodiment 1 of the present utility model: A desulfurized slurry flash evaporation waste heat recovery system for non-condensable gas desulfurization and vacuum extraction, which consists of an original desulfurization tower system and a desulfurized slurry flash evaporation heating and vacuum control subsystem. The original desulfurization tower system includes an original desulfurization tower 1, an original flue gas inlet pipe 2, and an original slurry pump 3. It is characterized in that the desulfurized slurry flash evaporation heating and vacuum control subsystem includes a high-vacuum flash evaporation tank 31, an absorption heat pump 36, a non-condensable gas desulfurization vacuum tank 39, a vacuum pump 18, a micro-pressure difference vacuum extraction device 38, and connecting pipelines and components. Among them, the slurry inlet of the high-vacuum flash evaporation tank 31 is connected to the waste heat slurry outlet of the bottom desulfurized slurry pool of the original desulfurization tower 1 through a waste heat slurry pump 10. The outlet of the final-stage concentrated slurry of the high-vacuum flash evaporation tank 31 is connected to the inlet of the original slurry pump 3 or the desulfurized slurry pool. The flash steam outlet of the high-vacuum flash evaporation tank 31 is connected to the heat source inlet of the evaporator 36c inside the absorption heat pump 36 through a final-stage connecting pipe 35. The heat source outlet of the evaporator 36c is connected to the inlet of the final-stage condensate pump 37. The absorption heat pump 36 also has a generator 36b and an absorber condenser assembly 36a communicated with the driving steam inside. The low-temperature water inlet of the absorber condenser assembly 36a is communicated with the water supply pipe of the return water H1 from the heat network. The low-temperature water outlet of the absorber condenser assembly 36a is communicated with the drain pipe of the return water H2 of the heat network. The outlet of the non-condensable gas S2 containing more SO2 on the heat source outlet side of the evaporator 36c is connected to the non-condensable gas inlet of the non-condensable gas desulfurization vacuum tank 39. The non-condensable gas desulfurization vacuum tank 39 is also provided with an alkali liquid spraying device 39a and a waterproof non-condensable gas suction device 39b inside. A hot well liquid level measurement and control component 39c is also provided below the lower liquid level and outside the tank body. Among them, the lower part of the alkali liquid spraying device 39a is the area of the non-condensable gas S2 containing more SO2, and the upper part is the area of the non-condensable gas S1 containing less SO2. The outlet of the final-stage condensate pump 37 is communicated with the drain pipe of the final-stage external discharged condensate water W2 through a mixing water regulating valve 39d. The outlet of the final-stage condensate pump 37 is also connected to the outlet of the alkali addition pump 30 and the inlet of the alkali liquid spraying device 39a. The inlet of the alkali addition pump 30 is communicated with the feed pipe of the sodium hydroxide solution Na. The bottom water outlet of the non-condensable gas desulfurization vacuum tank 39 is connected to the inlet of the final-stage condensate pump 37. The outlet of the waterproof non-condensable gas suction device 39b is connected to the air inlet of the micro-pressure difference vacuum extraction device 38. The exhaust outlet of the micro-pressure difference vacuum extraction device 38 is connected to the inlet of the vacuum pump 18. The exhaust outlet of the vacuum pump 18 is communicated with the original flue gas inlet pipe 2 of the original desulfurization tower 1. The upstream of the original flue gas inlet pipe 2 is the inlet of the original flue gas Y1 from the boiler outlet, and the downstream is the flue gas inlet of the original desulfurization tower 1. The top of the original desulfurization tower 1 is the outlet of the clean flue gas Y2. The sewage outlet of the bottom desulfurized slurry pool of the original desulfurization tower 1 is communicated with the drain pipe of the desulfurized wastewater P.
[0023] The preheater 26 adopts a vertical tube - type heat exchange structure or a horizontal tube - type heat exchange structure. When adopting the vertical tube - type heat exchange structure, a condensate hot well is arranged at the bottom, and a non - condensable gas discharge port is arranged above the liquid level of the hot well; when adopting the horizontal tube - type heat exchange structure, a non - condensable gas discharge port is arranged at the upper part of one end on the condensate outlet side.
[0024] The differential pressure vacuum extraction device 38 adopts one or more Roots compressors or negative pressure ejectors.
[0025] The vacuum pump 18 adopts a water - ring vacuum pump, a water jet air ejector or a Roots vacuum pump structure.
[0026] The outlet pipes of the pre - discharged condensate W1 and the final - stage discharged condensate W2 are respectively communicated with the inlet of the make - up water pipe of the desulfurization make - up water B and the make - up water pipe of the return water of the heat supply network H1.
[0027] Specific description of Embodiment 2 of the present utility model: On the basis of the specific Embodiment 1, when the temperature of the return water of the heat supply network H1 is lower than the difference between the temperature of the desulfurization slurry at the outlet of the waste heat slurry pump 10 minus 10 °C, a pre - flash tank 21 and a preheater 26 are further arranged in the desulfurization slurry flash heating and vacuum control subsystem. At this time, the slurry inlet of the pre - flash tank 21 is connected to the waste heat slurry outlet of the bottom desulfurization slurry tank of the original desulfurization tower 1 through the waste heat slurry pump 10, and the slurry outlet of the pre - flash tank 21 is connected to the slurry inlet of the high - vacuum flash tank 31; the flash steam outlet of the pre - flash tank 21 is connected to the steam inlet of the preheater 26 through a pre - connecting pipe 25, the condensate outlet of the preheater 26 is connected to the inlet of the pre - condensate pump 27, and the outlet of the pre - condensate pump 27 is communicated with the outlet pipe of the pre - discharged condensate W1; the low - temperature water inlet of the preheater 26 is communicated with the incoming water pipe of the return water of the heat supply network H1, and the low - temperature water outlet of the preheater 26 is connected to the low - temperature water inlet of the absorber - condenser assembly 36a of the absorption heat pump 36; the outlet of the pre - non - condensable gas S on the condensate liquid level of the bottom hot well of the preheater 26 is connected to the inlet of the vacuum pump 18; the condensate outlet of the non - condensable gas desulfurization vacuum tank 39 is connected to the inlet of the desulfurization tank drain pump 39e, and the outlet of the desulfurization tank drain pump 39e is communicated with the outlet pipe of the final - stage discharged condensate W2.
[0028] It should be noted that the present utility model is based on the key technologies of reducing components such as SO2 by chemical and physical methods for the non-condensable gas generated from the condensate of the flash steam of the desulfurization slurry, thereby significantly reducing the total amount of non-condensable gas and improving the vacuum degree. A complete set of brand-new integrated systems for flash evaporation of desulfurization slurry, direct heater and cascaded heating of absorption heat pump are proposed for deep flue gas waste heat recovery of flue gas. According to this overall solution, there can be different specific implementation measures and specific implementation devices with different structures. The above specific implementation manners are just one of them. Any other similar simple deformed implementation manners, such as changing the type, number of stages, and combination mode of the compressor, simple deformation of the relevant flash steam and heat exchanger, and simple adjustment of the relevant pipelines, or simple changes in the vacuum pumping method and the recovery and utilization method of condensate, etc., all fall within the protection scope of the present utility model.
Claims
1. A desulfurization slurry flash heat recovery system for vacuuming non-condensable gas desulfurization, comprising an original desulfurization tower system and a desulfurization slurry flash heating and vacuum control subsystem, wherein the original desulfurization tower system comprises an original desulfurization tower (1), an original flue gas inlet pipe (2) and an original slurry pump (3), characterized in that: The desulfurization slurry flash heating and vacuum control subsystem comprises a high vacuum flash tank (31), an absorption heat pump (36), a non-condensable gas desulfurization vacuum tank (39), a vacuum pump (18), a micro-pressure differential vacuum pump (38) and connecting pipelines and components, wherein the slurry inlet of the high vacuum flash tank (31) is connected to the waste heat slurry outlet of the desulfurization slurry pool at the bottom of the original desulfurization tower (1) through a waste heat slurry pump (10), and the final concentrated slurry outlet of the high vacuum flash tank (31) is connected to the inlet of the original slurry pump (3) or the desulfurization slurry pool; the flash steam outlet of the high vacuum flash tank (31) is connected to the heat source of the evaporator (36c) inside the absorption heat pump (36) through the final connecting pipe (35). The heat source outlet of the evaporator (36c) is connected to the inlet of the final condensation pump (37); the absorption heat pump (36) is further provided with a generator (36b) in communication with the driving steam and an absorber condenser assembly (36a); the low-temperature water inlet of the absorber condenser assembly (36a) is in communication with the water inlet pipe of the return water (H1) of the heat network, and the low-temperature water outlet of the absorber condenser assembly (36a) is in communication with the water return pipe of the return water (H2) of the heat network; the outlet of the non-condensable gas (S2) containing a lot of SO2 on the heat source outlet side of the evaporator (36c) is connected to the non-condensable gas inlet of the non-condensable gas desulfurization vacuum tank (39), and the non-condensable gas desulfurization vacuum tank (39) is further provided with an alkali solution spraying device. The tank body is provided with a hot well liquid level measuring and controlling component (39c) below the lower liquid level and outside the tank body, wherein the lower part of the alkali solution spraying device (39a) is a region containing more SO2 non-condensable gas (S2), and the upper part is a region containing less SO2 non-condensable gas (S1); the outlet of the final stage condensation pump (37) is connected to the outlet pipe of the final stage condensate (W2) through the mixed water regulating valve (39d), the outlet of the final stage condensation pump (37) is also connected to the outlet of the alkali adding pump (30) and the inlet of the alkali solution spraying device (39a), and the inlet of the alkali adding pump (30) is connected to the feed pipe of the sodium hydroxide solution (Na); the non-condensable gas desulfurization vacuum tank The bottom water outlet of (39) is connected to the water inlet of the final stage condensation pump (37); the outlet of the waterproof non-condensable gas suction device (39b) is connected to the air inlet of the micro-pressure difference vacuum pump (38); the exhaust port of the micro-pressure difference vacuum pump (38) is connected to the inlet of the vacuum pump (18); the exhaust port of the vacuum pump (18) is connected to the original flue gas inlet pipe (2) of the original desulfurization tower (1); the upstream of the original flue gas inlet pipe (2) is the inlet of the original flue gas (Y1) from the boiler outlet, the downstream is the flue gas inlet of the original desulfurization tower (1), the top of the original desulfurization tower (1) is the outlet of the clean flue gas (Y2), and the sewage outlet of the desulfurization slurry pool at the bottom of the original desulfurization tower (1) is connected to the drainage pipe of the desulfurization wastewater (P).
2. A non-condensable gas desulfurization vacuum desulfurization slurry flash evaporation waste heat recovery system as claimed in claim 1, characterized in that When the temperature of the return water (H1) of the heating network is lower than the temperature of the desulfurization slurry at the outlet of the waste heat slurry pump (10) minus 10°C, the desulfurization slurry flash heating and vacuum control subsystem is further provided with a pre-flash tank (21) and a pre-heater (26). At this time, the slurry inlet of the pre-flash tank (21) is connected to the waste heat slurry outlet of the desulfurization slurry pool at the bottom of the original desulfurization tower (1) through the waste heat slurry pump (10), and the slurry outlet of the pre-flash tank (21) is connected to the slurry inlet of the high vacuum flash tank (31); the flash steam outlet of the pre-flash tank (21) is connected to the steam inlet of the pre-heater (26) through the pre-connecting pipe (25), and the condensate outlet of the pre-heater (26) is connected to the pre-condensate pump ( The inlet of the pre-condensation pump (27) is connected to the inlet of the pre-discharge condensate (W1); the outlet of the pre-condensation pump (27) is connected to the outlet pipe of the pre-discharge condensate (W1); the low-temperature water inlet of the pre-heater (26) is connected to the inlet pipe of the heat network return water (H1), and the low-temperature water outlet of the pre-heater (26) is connected to the low-temperature water inlet of the absorber condenser component (36a) of the absorption heat pump (36); the outlet of the pre-condensate gas (S) on the condensate liquid surface of the bottom hot well of the pre-heater (26) is connected to the inlet of the vacuum pump (18); the condensate outlet of the non-condensable gas desulfurization vacuum tank (39) is connected to the inlet of the desulfurization tank drainage pump (39e), and the outlet of the desulfurization tank drainage pump (39e) is connected to the outlet pipe of the final stage discharge condensate (W2).
3. A non-condensable gas desulfurization vacuum desulfurization slurry flash evaporation waste heat recovery system as claimed in claim 2, characterized in that The preheater (26) adopts a vertical shell-and-tube heat exchange structure or a horizontal shell-and-tube heat exchange structure, wherein when the vertical shell-and-tube heat exchange structure is adopted, a condensate hot well is arranged at the bottom, and a non-condensable gas discharge outlet is arranged above the hot well liquid surface; when the horizontal shell-and-tube heat exchange structure is adopted, a non-condensable gas discharge outlet is arranged at the upper part of one end on the condensate outlet side.
4. A desulfurization slurry flash evaporation waste heat recovery system for non-condensable gas desulfurization and vacuum pumping as claimed in claim 1, characterized in that The micro-pressure difference vacuum pumping device (38) adopts one or more Roots compressors or negative pressure ejectors.
5. A desulfurization slurry flash evaporation waste heat recovery system for non-condensable gas desulfurization and vacuum pumping as claimed in claim 1, characterized in that The vacuum pump (18) adopts a water ring vacuum pump, a water jet steam extractor or a Roots vacuum pump structure.
6. A non-condensable gas desulfurization vacuum desulfurization slurry flash evaporation waste heat recovery system as claimed in claim 2, characterized in that The outlet pipes of the front-stage externally discharged condensed water (W1) and the final-stage externally discharged condensed water (W2) are respectively connected to the inlet pipes of the desulfurization feed water (B) and the heat network return water (H1).