Waste heat recovery system for waste power station boiler slag

Abstract

The invention belongs to the technical field of boiler waste heat recovery, and particularly discloses a waste power station boiler slag waste heat recovery system which comprises a flash tank, a first waste slag storage tank, a vacuum pump, a sprayer and an organic Rankine cycle system. The first waste residue storage tank is connected with the flash tank and conveys high-temperature slag into the tank; the vacuum pump is used for adjusting internal pressure of the flash tank to reduce boiling point of water; the sprayer is arranged in the flash tank and is used for spraying water to the high-temperature slag to generate water vapor; the organic Rankine cycle system comprises an evaporator connected to an outlet in the top of the flash tank, a turbo expander for converting heat energy of the evaporator into mechanical energy, a generator for converting the mechanical energy into electric energy, a condenser for cooling an organic working medium and an organic working medium storage tank for storing the organic working medium. According to the system, by optimizing the heat exchange process and the system design, the waste heat recovery efficiency can be remarkably improved, the influence on the environment is reduced, and waste residue resource utilization is promoted while low-grade waste heat is converted into high-grade electric energy.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler waste heat recovery, and particularly to a waste heat recovery system for the slag of a garbage power plant boiler. Background Art

[0002] With the continuous advancement of the global industrialization and urbanization processes, the problem of garbage disposal has become increasingly prominent. As an effective way to convert urban domestic garbage into energy, garbage power plants have been widely used. During the operation of a garbage power plant, the high-temperature slag generated by the boiler contains rich waste heat resources. According to statistics, the waste heat of the slag accounts for 3-5% of the total calorific value of garbage incineration. If it is directly discarded, it will not only cause energy waste, but also increase the water consumption of the cooling system and the subsequent sewage treatment cost. The traditional treatment methods for the slag of garbage power plant boilers mainly include the water quenching technology and the air quenching technology. The disadvantage of the water quenching technology is the large consumption of water resources, low waste heat recovery efficiency, high wastewater treatment cost, and possible environmental pollution problems; although the air quenching method avoids the high water consumption problem of water quenching, the waste heat recovery efficiency is still low, and it has the disadvantages of complex equipment, high operating cost, and serious dust pollution.

[0003] In view of the above problems, the present invention proposes a waste heat recovery system for the slag discharged from a garbage power plant boiler, aiming to efficiently recover the waste heat in the high-temperature slag and at the same time reduce the equipment operation and maintenance costs. Summary of the Invention

[0004] The purpose of the present invention is to provide a waste heat recovery system for the slag of a garbage power plant boiler to solve the above-mentioned technical problems existing in the prior art.

[0005] To achieve the above purpose, the present invention provides the following solution: A waste heat recovery system for the slag of a garbage power plant boiler, comprising:

[0006] A flash tank;

[0007] A first waste residue storage tank, connected to the flash tank, for transporting high-temperature slag into the flash tank;

[0008] A vacuum pump, connected to the flash tank, for adjusting the internal pressure of the flash tank to reduce the boiling point of water;

[0009] A sprayer, arranged in the flash tank, for spraying water on the high-temperature slag to generate water vapor;

[0010] An organic Rankine cycle system, comprising an evaporator connected to the top outlet of the flash tank, a turbine expander connected to the evaporator and converting the heat energy of the evaporator into mechanical energy, a generator connected to the turbine expander and converting the mechanical energy into electrical energy, a condenser for cooling the organic working fluid discharged from the turbine expander, and an organic working fluid storage tank for storing and circulating the supply of the organic working fluid.

[0011] In some alternative embodiments of the present invention, a hydrophobic molecular sieve is installed near the top steam outlet of the flash tank for filtering particulate matter and acidic gases in the steam.

[0012] In some alternative embodiments of the present invention, the hydrophobic molecular sieve is selected as a zeolite-based composite material.

[0013] In some alternative embodiments of the present invention, the particle size of the hydrophobic molecular sieve is 0.5 - 1 mm, and the adsorption capacity is ≥ 50%.

[0014] In some alternative embodiments of the present invention, the organic working fluid is pentane or hydrofluorocarbon.

[0015] In some alternative embodiments of the present invention, the sprayer is connected to the condenser through a pipeline, and a second working fluid pump is provided on the pipeline to realize the recycling of the spray water.

[0016] In some alternative embodiments of the present invention, multi-stage pressure-reducing flashing is carried out in stages in the flash tank. The pressure in the first stage is controlled at 10 - 30 kPa, and the pressure in the second stage is reduced to 5 - 15 kPa to gradually extract the waste heat in the high-temperature slag.

[0017] In some alternative embodiments of the present invention, a pressure gauge is provided in the flash tank to monitor the pressure change in the tank in real time.

[0018] In some alternative embodiments of the present invention, the sprayer has multiple nozzles and is provided with a flow controller.

[0019] In some alternative embodiments of the present invention, the bottom slag discharge port of the flash tank is connected to a second waste slag storage tank for storing the cooled waste slag.

[0020] Compared with the prior art, the present invention discloses at least the following beneficial effects:

[0021] By optimizing the heat exchange process and system design, the system of the present invention can significantly improve the waste heat recovery efficiency, reduce the impact on the environment, convert low-grade waste heat into high-grade electric energy, promote the resource utilization of waste slag, realize the efficient recovery and utilization of waste heat, and promote the green transformation of the waste incineration industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1This is a structural diagram of the waste heat recovery system of the boiler slag of the garbage power station of the present invention;

[0024] In the figure: 1. first waste residue storage tank; 2. second waste residue storage tank; 3. flash tank; 4. sprayer; 5. first working fluid pump; 6. evaporator; 7. organic working fluid storage tank; 8. turbine expander; 9. generator; 10. condenser; 11. second working fluid pump; 12. third working fluid pump; 13. valve one; 14. valve two; 15. valve three; 16. vacuum pump; 17. pressure gauge; 18. hydrophobic molecular sieve. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The existing waste heat recovery technologies for boiler slag in garbage power plants include water quenching and air quenching. For example, the water quenching method requires a large amount of water to cool the high-temperature slag, which will lead to a large consumption of water resources. In addition, the wastewater generated during the water quenching process needs to be treated before it can be discharged, which not only increases the cost of wastewater treatment, but also may cause harmful substances contained in the slag to dissolve into the water, causing environmental pollution problems. The air quenching method still has significant defects in the waste heat recovery of boiler slag in garbage power plants. Although it avoids the high water consumption and secondary pollution problems of the water quenching process, the waste heat recovery efficiency is low (due to the small heat capacity of air and insufficient heat exchange rate). During the cooling process, the slag particles are easily bonded or broken due to uneven airflow distribution, affecting the quality of the slag and subsequent resource utilization. At the same time, the slag dust entrained by the high-speed airflow is easy to aggravate equipment wear and pipeline blockage, and an efficient dust removal system is required to avoid dust leakage and environmental pollution. In addition, the energy consumption of the high-power fan is high when it is continuously operated, which is contrary to the overall energy efficiency improvement goal, and it is difficult to achieve stable recovery and efficient integrated utilization of waste heat.

[0027] In order to solve the problems of the current water quenching method for recovering waste heat from boiler slag in garbage power plants, which consumes a lot of water resources and causes secondary pollution; the wind quenching method has low waste heat recovery efficiency, dust easily pollutes the environment, and has high requirements on equipment performance, the present invention constructs a waste heat recovery system for boiler slag in garbage power plants with low pollution, high waste heat utilization rate and low operating cost, which promotes the conversion of low-grade waste heat energy into high-grade energy such as electricity.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Reference Figure 1As shown in the figure, the present invention provides a waste power station boiler slag waste heat recovery system, which includes a slag feeding and flash evaporation system, an organic Rankine cycle system, and a waste residue discharging and resource utilization system. Each system is interconnected through pipelines, valves, and pumps to form a complete waste heat recovery system.

[0030] Specifically, the slag feeding and flash evaporation system includes a first waste residue storage tank 1, a flash evaporation tank 3, a sprayer 4, a vacuum pump 16, a pressure gauge 17, and a hydrophobic molecular sieve 18. Among them, the first waste residue storage tank 1 is used to store the high-temperature waste slag discharged from the waste power station boiler, and its discharge port is connected to the feed port of the flash evaporation tank 3 through a pipeline for transporting the high-temperature slag into the flash evaporation tank 3.

[0031] In a specific embodiment, the flash evaporation tank 3 serves as the main reactor for flash evaporation operation. Its feed port is connected to the first waste residue storage tank 1, and the top is connected to the evaporator 6 through a pipeline. A valve 13 and a first working medium pump 5 are installed on the pipeline for transporting the high-temperature water vapor to the evaporator 6. A hydrophobic molecular sieve 18 is also installed near the top inside the flash evaporation tank 3 for filtering impurities in the steam, reducing the scaling or blockage of the pipeline for transporting water vapor; the bottom of the flash evaporation tank 3 is connected to the second waste residue storage tank 2 through a slag discharge port for discharging the cooled waste slag; the inside of the flash evaporation tank 3 is connected to the suction port of the vacuum pump 16 through a pipeline for adjusting the pressure inside the tank; a pressure gauge 17 is also installed inside the tank for real-time monitoring of the pressure inside the tank.

[0032] In a specific embodiment, the sprayer 4 is installed inside the flash evaporation tank 3 and is connected to the outlet of the second working medium pump 11 through a pipeline for spraying water on the high-temperature slag inside the flash evaporation tank 3. The water absorbs the heat of the high-temperature waste slag at the bottom of the container and turns into water vapor and high-temperature water.

[0033] In a specific embodiment, the suction port of the vacuum pump 16 is connected to the inside of the flash evaporation tank 3 through a pipeline for reducing the pressure inside the flash evaporation tank 3, thereby reducing the boiling point of the liquid and enabling the liquid to vaporize rapidly at a lower temperature, achieving rapid evaporation and separation of the liquid.

[0034] In a specific embodiment, the pressure gauge 17 is installed inside the flash evaporation tank 3 for real-time monitoring of the pressure change inside the tank to ensure that the flash evaporation process is carried out within the set pressure range.

[0035] In a specific embodiment, the hydrophobic molecular sieve 18 is installed near the steam outlet at the top inside the flash evaporation tank 3 for filtering impurities in the steam. Through the dual actions of physical adsorption and chemical inertness, it efficiently intercepts the slag microparticles (particle size ≤ 50μm) and acidic gases (such as SO2, HCl) carried in the steam, effectively avoiding pipeline scaling, corrosion, and dust pollution, while ensuring the steam purity to meet the stable operation requirements of the ORC system.

[0036] In an optional embodiment, the hydrophobic molecular sieve 18 is made of a zeolite-based composite material with a particle size of 0.5-1 mm and an adsorption capacity ≥ 50%. It should be understood that the selection of the hydrophobic molecular sieve 18 is only an optional method and not the only limitation.

[0037] Specifically, the organic Rankine cycle system includes an evaporator 6, an organic working fluid storage tank 7, a turbine expander 8, a generator 9, a condenser 10 and a third working fluid pump 12. The steam inlet of the evaporator 6 is connected to the top of the flash tank 3 through a pipeline, a valve 13 and a first working fluid pump 5 are installed on the pipeline, the steam outlet is connected to the inlet of the turbine expander 8 through a pipeline, and the inside of the evaporator 6 is connected to the organic working fluid storage tank 7 through a pipeline for receiving the organic working fluid. The evaporator 6 absorbs heat by contacting with high-temperature water vapor, and transfers the heat to the organic working fluid, thereby heating the organic working fluid and converting it into steam.

[0038] In the embodiment of the present invention, a technology of multi-stage flash evaporation and organic Rankine cycle (ORC) is adopted to reduce the pressure step by step in stages through the vacuum flash tank 3. For example, the first-stage flash evaporation designed in the system recovers high-temperature steam, and the second-stage flash evaporation further extracts the waste heat of residual liquid water. In combination with the ORC system, the low-grade thermal energy generated by the flash evaporation is converted into electrical energy through the organic Rankine cycle, thereby maximizing the cascade utilization of waste heat and improving the thermal efficiency, which is significantly better than the traditional single water quenching or air quenching process.

[0039] In a specific embodiment, the organic working fluid storage tank 7 stores organic working fluids for an organic Rankine cycle, such as pentane and HFC (hydrofluorocarbons), and its outlet is connected to the evaporator 6 through a pipeline. A valve 3 15 is installed on the pipeline for conveying the organic working fluid to the evaporator 6, and its inlet is connected to the condenser 10 through a pipeline for receiving the condensed organic working fluid liquid.

[0040] In a specific embodiment, the turbo expander 8 is used to convert the internal energy (heat energy and pressure energy) of the high-pressure gas into mechanical energy, and its inlet is connected to the steam outlet of the evaporator 6 through a pipeline, and its outlet is connected to the generator 9 through a pipeline to drive the generator 9 to work. The generator 9 is connected to the turbo expander 8 and is used to convert the mechanical work output by the turbo expander 8 into electrical energy, thereby realizing the effective utilization of low-grade thermal energy.

[0041] In a specific embodiment, the condenser 10 is used to cool and condense the organic working fluid steam discharged from the turbine expander 8 into a liquid state. Its inlet is connected to the outlet of the turbine expander 8 through a pipeline, and its outlet is connected to the organic working fluid storage tank 7 through a pipeline, for sending the condensed organic working fluid liquid back to the storage tank. The third working fluid pump 12 is arranged on the pipeline between the condenser 10 and the organic working fluid storage tank 7, for providing the reflux power to pump the condensed organic working fluid liquid back to the organic working fluid storage tank 7.

[0042] Specifically, the waste residue discharging and resource utilization system includes a second waste residue storage tank 2 and a second working fluid pump 11. The second waste residue storage tank 2 is arranged at the bottom of the flash tank 3 and is connected to the slag discharge port of the flash tank 3, for receiving and storing the cooled waste residue. The second working fluid pump 11 is used to pressurize and pump the circulating water into the sprayer 4 for recycling. Its inlet is connected to the drain outlet of the condenser 10 through a pipeline, for receiving the condensed water, and its outlet is connected to the sprayer 4 through a pipeline, for pressurizing and transporting the condensed water to the sprayer 4 to realize the recycling of the spray water.

[0043] It should be understood that in practical applications, the number of nozzles of the sprayer 4 can be set to be multiple, and a flow controller is arranged on the nozzle to control the flow rate of the spray water sprayed by the sprayer 4 in real time.

[0044] The embodiment of the present invention also provides a method for recovering the waste heat of the slag of a waste power station boiler. Based on the waste heat recovery system of the slag of the waste power station boiler described in the above embodiment, its operation process is as follows:

[0045] S1. System startup and initialization

[0046] S11. Equipment inspection: Before the system starts, check whether the connections of all equipment are firm and whether the valves are in the closed state to ensure good system sealing;

[0047] S12. When the system starts to work, start the vacuum pump 16 to evacuate the flash tank 3, and reduce the pressure in the tank to the first preset value (for example, 10 KPa), so as to reduce the boiling point of water and promote the vaporization of water;

[0048] S13. Close the first valve 13, the second valve 14, and the third valve 15, and stop the first working fluid pump 5, the second working fluid pump 11, and the third working fluid pump 12.

[0049] S2. Slag feeding and flashing process

[0050] S21. Open the discharge port of the first waste residue storage tank 1, and control the high-temperature slag discharged from the waste power station boiler to enter the flash tank 3 through the feed port switch. The slag temperature is about 500 °C;

[0051] S22. Start the sprayer 4 and sprinkle water on the high-temperature slag at the bottom of the flash tank 3 at a specific flow rate (such as 20 L / min). After the water absorbs the heat of the high-temperature slag, high-temperature water vapor and a part of high-temperature liquid water are mixed in the slag.

[0052] S23. Open the first valve 13 and start the first working fluid pump 5. Send the high-temperature water vapor into the evaporator 6 as a heat source by pressurization; during the process of extracting the high-temperature water vapor, it is filtered through the hydrophobic molecular sieve 18 to remove the boiler slag particles and some toxic gases contained in the steam, avoiding the blockage and corrosion of the gas transmission pipeline.

[0053] S24. Multi-stage flash evaporation: After extracting the high-temperature water vapor, close the first valve 13 and the first working fluid pump 5, start the vacuum pump 16 again to reduce the pressure, and precisely adjust it to the second preset value (such as 5 kPa) through the pressure gauge 17 to further convert the high-temperature liquid water mixed in the slag into thermal steam, maximizing the waste heat recovery. After completion, reopen the first valve 13 and the first working fluid pump 5, and send the generated thermal steam into the evaporator 6.

[0054] In the above embodiment, the pressure in the tank is monitored in real time through the pressure gauge 17, and the vacuum pump 16 precisely adjusts the pressure in the flash tank 3 at the same time (for example, the first-stage pressure is controlled at 10 - 30 kPa, and the second stage is reduced to 5 - 15 kPa), controlling the spray water volume and the system slag inlet rate. The entire flash evaporation process is efficient and stable, and the dynamic regulation of the flash evaporation pressure can adapt to the temperature fluctuation (300 - 600 °C) and composition difference of the slag.

[0055] In the above embodiment, the multi-stage flash evaporation technology is adopted. Through heat exchange in multiple stages, heat can be recovered more fully, and different flash evaporation stages can be designed according to different pressure and temperature conditions, with high thermal efficiency and good flexibility. The present invention utilizes the principle of the organic Rankine cycle, and the system has the advantages of simple structure and low operating cost, and can utilize the characteristics of the low boiling point of the organic working fluid, which is easy to vaporize and expand, effectively converting low-grade thermal energy into high-grade electrical energy, and effectively realizing the waste heat recovery of the boiler slag in the waste power station.

[0056] S3. Organic Rankine cycle process

[0057] S31. Evaporation of the organic working fluid: Open the third valve 15, and the organic working fluid flows from the organic working fluid storage tank 7 into the evaporator 6, absorbing the heat of the high-temperature water vapor and evaporating the organic working fluid into steam; the organic working fluid adopted in this embodiment is pentane.

[0058] S32. Turbine expansion and power generation: The evaporated organic working fluid steam enters the turbine expander 8 to expand and do work, driving the generator 9 to work and converting thermal energy into electrical energy.

[0059] S33. Condensation and Circulation: The expanded organic working fluid vapor enters the condenser 10 and condenses into a liquid. The condensed liquid working fluid is sent back to the organic working fluid storage tank 7 through the third working fluid pump 12 to complete a cycle.

[0060] S34. Spray Water Circulation: The water used for condensation is re - conveyed to the sprayer 4 through the second working fluid pump 11 for recycling.

[0061] In this embodiment, the spray water is reused in combination with the condensed water through the second working fluid pump 11, and the multi - stage flash evaporation is used to dynamically adjust the water - vapor balance, realizing zero external discharge of water resources; the organic working fluid (such as pentane, HFC) completes the full - closed - loop flow of evaporation - expansion - condensation - pressurization in the organic Rankine cycle (ORC) system, avoiding the risk of working fluid loss and environmental leakage, and significantly reducing the water consumption of the system.

[0062] S4. Waste Residue Discharge and Resource Utilization

[0063] S41. Waste Residue Discharge: After absorbing the waste heat, the temperature of the waste residue drops below 80 °C and is discharged from the slag discharge port at the bottom of the flash tank 3 and collected in the second waste residue storage tank 2.

[0064] S42. Waste Residue Resource Utilization: The waste residue in the second waste residue storage tank 2 is conveyed to the building materials production line. After being crushed and screened, it is used to prepare environmental - protection bricks or subgrade materials, realizing the resource utilization of the waste residue.

[0065] The low - temperature slag (≤80 °C) after waste heat recovery is stored in the second waste residue storage tank 2 through the discharge port; if necessary, the waste heat power station can directly convey it to the building materials production line. After being crushed and screened, it is used to prepare environmental - protection bricks or subgrade materials, and this part of the waste residue is utilized; forming a dual - path circular economy chain of "waste heat power generation - waste residue utilization", avoiding the secondary pollution problem caused by the slag - water mixture in the traditional water quenching method.

[0066] The waste heat recovery system for the boiler slag of the waste heat power station and its operation method recorded in the embodiments of the present invention at least disclose the following beneficial effects:

[0067] 1. The present invention proposes a waste heat recovery system for the boiler slag of the waste heat power station, which has low pollution, high energy utilization rate, simple devices used, low operation cost, convenient operation and high feasibility.

[0068] 2. The present invention uses the multi - stage flash evaporation technology to evaporate by gradually reducing the pressure in stages, can efficiently recover and utilize waste heat, significantly improve the energy utilization efficiency, and at the same time has a large processing capacity and strong stability.

[0069] 3. The present invention utilizes the characteristic of low boiling point of the organic working fluid in the organic Rankine cycle technology to efficiently recover medium and low temperature heat sources. The system has a simple structure and stable operation, and has the advantages of environmental protection and low maintenance cost. In addition to being used in the waste heat recovery of the boiler slag of the waste power station, it can also be widely applied to the low-grade heat energy power generation fields such as the industrial waste heat of the boiler slag in the steel plant.

[0070] 4. The organic working fluid and condensate in this system can be recycled in the system to reduce the waste of resources.

[0071] 5. This system utilizes the hydrophobic molecular sieve 18, which can effectively absorb the small particles of slag in the water vapor and effectively avoid the blockage of the gas transmission pipeline.

[0072] 6. This system is based on the multi-stage flash-ORC collaborative technology, which is deeply integrated with the environmental protection energy industry. By efficiently recovering the waste heat of garbage incineration for power generation, it realizes the energyization of solid waste, and at the same time avoids the problems of high water consumption and secondary pollution of the water quenching method.

[0073] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0074] The embodiments described above are only for describing the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solution of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A waste power station boiler slag waste heat recovery system, characterized in that, Including: Flash tank (3); The first waste residue storage tank (1), which is connected to the flash tank (3) and conveys high-temperature slag into the flash tank (3); Vacuum pump (16), which is connected to the flash tank (3) and is used to adjust the internal pressure of the flash tank (3) to reduce the boiling point of water; Sprinkler (4), which is arranged in the flash tank (3) and is used to sprinkle water on the high-temperature slag to generate water vapor; Organic Rankine cycle system, including an evaporator (6) connected to the top outlet of the flash tank (3), a turbine expander (8) connected to the evaporator (6) and converting the thermal energy of the evaporator (6) into mechanical energy, a generator (9) connected to the turbine expander (8) and converting mechanical energy into electrical energy, a condenser (10) used to cool the organic working fluid discharged from the turbine expander (8), and an organic working fluid storage tank (7) used to store and recycle the supply of organic working fluid.

2. The waste power station boiler slag waste heat recovery system according to claim 1, wherein, A hydrophobic molecular sieve (18) is installed near the top steam outlet of the flash tank (3) to filter particulate matter and acidic gases in the steam.

3. The waste power station boiler slag waste heat recovery system according to claim 2, characterized in that, The hydrophobic molecular sieve (18) is made of a zeolite-based composite material.

4. The waste power station boiler slag waste heat recovery system according to claim 3, characterized in that The particle size of the hydrophobic molecular sieve (18) is 0.5 - 1 mm, and the adsorption capacity ≥ 50%.

5. The waste power station boiler slag waste heat recovery system according to claim 1, wherein The organic working fluid is pentane or hydrofluorocarbon.

6. The waste power station boiler slag waste heat recovery system according to claim 1, wherein, The sprinkler (4) is connected to the condenser (10) through a pipeline, and a second working fluid pump (11) is provided on the pipeline to realize the recycling of the spray water.

7. The waste power station boiler slag waste heat recovery system according to claim 1, characterized in that, Multi-stage pressure reduction flashing is carried out in stages in the flash tank (3). The pressure in the first stage is controlled at 10 - 30 kPa, and the pressure in the second stage is reduced to 5 - 15 kPa to gradually extract the waste heat in the high-temperature slag.

8. The waste power station boiler slag waste heat recovery system according to claim 1, characterized in that, A pressure gauge (17) is arranged in the flash tank (3) to monitor the pressure change in the tank in real time.

9. The waste power station boiler slag waste heat recovery system according to claim 1, wherein, The sprinkler (4) has a plurality of nozzles and is provided with a flow controller.

10. The waste power station boiler slag waste heat recovery system according to claim 1, characterized in that, The bottom slag outlet of the flash tank (3) is connected to a second waste residue storage tank (2) for storing the cooled slag.

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