High-parameter large-flow saturated steam cascade utilization waste heat recovery system and control method

Abstract

The application provides a high-parameter large-flow saturated steam step utilization waste heat recovery system and a control method, and belongs to the technical field of metal smelting and power generation. The system comprises a high-pressure steam source, a high-low pressure steam power generation system, a first power generation structure, two groups of second power generation structures, a first steam proportion adjusting assembly, a second steam proportion adjusting assembly and a temperature and pressure reducing assembly. The first power generation structure is used for receiving high-parameter large-flow saturated steam generated by the high-pressure steam source and generating power. The system further comprises a low-pressure steam pipe network and a condensation circulation system. The saturated steam enters a back pressure steam turbine after one-stage dehumidification, expands to work and then enters the low-pressure steam pipe network. The low-pressure steam pipe network distributes low-pressure steam to an external network for production, life steam and deoxygenation steam. The remaining steam enters a pure condensation type saturated steam turbine after two-stage dehumidification and generates power. The system embodies the idea of "demand distribution and step utilization" and realizes the maximization of waste heat resource utilization efficiency.

Description

Technical Field

[0001] This invention belongs to the field of metal smelting power generation technology, specifically relating to a high-parameter, high-flow-rate saturated steam cascade utilization waste heat recovery system and control method. Background Technology

[0002] The production processes of steel, non-ferrous metal smelting, and cement manufacturing generate large amounts of high-temperature flue gas. High-pressure steam sources can convert this high-temperature flue gas into saturated steam. The saturated steam then enters a saturated steam turbine, converting the steam's thermal energy into mechanical energy, which drives power generation equipment to produce electricity, turning waste into treasure and reducing environmental pollution. Currently, most of the saturated steam waste heat utilization technologies developed both domestically and internationally are small-flow saturated steam turbines, resulting in poor cascade utilization efficiency and making it difficult to maximize the utilization efficiency of waste heat resources. Summary of the Invention

[0003] The technical problem to be solved by this invention is the insufficient utilization of high-parameter, high-flow-rate steam. In view of the shortcomings of the prior art, this invention provides a waste heat recovery system and control method for high-parameter, high-flow-rate saturated steam that can be utilized in stages.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A high-parameter, high-flow-rate saturated steam cascade utilization waste heat recovery system is characterized by a high- and low-pressure steam power generation system. The high- and low-pressure steam power generation system includes a first power generation structure and two sets of second power generation structures. The first power generation structure generates power using high-parameter, high-flow-rate saturated steam produced by the high-pressure steam source and produces low-pressure saturated steam. The second power generation structures generate power using the low-pressure saturated steam and discharge steam. The system also includes a first steam proportioning component, a second steam proportioning component, and a desuperheating and pressure reducing component. The desuperheating and pressure reducing component is connected in parallel with the first power generation structure. The desuperheating and pressure reducing component converts the high-parameter, high-flow-rate saturated steam into low-pressure saturated steam. The first steam proportioning component adjusts the proportion of the high-parameter, high-flow-rate saturated steam entering the first power generation structure and the desuperheating and pressure reducing component. The second steam proportioning component adjusts the proportion of low-pressure saturated steam flowing into the two sets of second power generation structures. A low-pressure steam pipeline network is used to transmit the low-pressure saturated steam and to supply the low-pressure saturated steam to production, domestic use, and condensation and deoxygenation. A condensation circulation system is provided, which receives steam discharged from the second power generation structure, condenses the steam to form circulating water, and uses the cooled circulating water to transport heat to the high-pressure steam source.

[0005] Furthermore, the condensation circulation system includes a condenser, a cooling tower, a heat exchange station, a heat user, a condensate pump, a shaft seal heater, a deaerator, and a heat pipe boiler. The main steam outlet of the second power generation structure is connected to the condenser. The condenser has two sets of circulating water outlets. One set of circulating water outlets is connected to the cooling tower, and the other set of circulating water outlets is connected in sequence to the heat exchange station, the heat user, and the cooling tower. The outlet of the cooling tower is connected to the condenser. The condensate outlet of the condenser is connected in sequence to the condensate pump, the shaft seal heater, the deaerator, the feedwater pump, and the heat pipe boiler. The heat pipe boiler heats and generates steam, which is then used for the low-pressure steam network.

[0006] Furthermore, the low-pressure steam network includes a bypass channel, a power generation steam channel, and a deaeration steam channel, as well as an industrial steam channel, a domestic steam channel, and a bypass channel. The low-pressure steam network is used to redistribute low-pressure saturated steam into the power generation steam channel, the industrial steam channel, the domestic steam channel, the bypass channel, and the deaeration steam channel.

[0007] Furthermore, the high-pressure steam source includes a waste heat boiler, the first steam proportional regulation component includes a first proportional regulation valve, the second steam proportional regulation component includes a second proportional regulation valve, the steam outlet of the first power generation structure is connected to a four-way connector, the desuperheating and pressure reducing component includes a desuperheating and pressure reducing device, both the first proportional regulation valve and the second proportional regulation valve include a steam inlet and two sets of steam outlets, the steam inlet of the first proportional regulation valve is connected to the waste heat boiler, the two sets of steam outlets of the first proportional regulation valve are respectively connected to the first power generation structure and the desuperheating and pressure reducing device, the steam outlets of the first power generation structure and the desuperheating and pressure reducing device are connected to the air inlet of the four-way connector, the steam inlet of the second proportional regulation valve is connected to the steam outlet of the four-way connector, and the steam outlet of the second proportional regulation valve is respectively connected to two sets of the second power generation structure.

[0008] Furthermore, the first power generation structure includes a high-pressure steam-water separator, a high-pressure suspended main steam valve, a high-parameter back-pressure saturated steam turbine, and a first generator. The steam inlet of the high-pressure steam-water separator is connected to the high-parameter, high-flow-rate saturated steam outlet of the waste heat boiler. The outlet of the high-pressure steam-water separator is connected to the main steam inlet of the high-pressure suspended main steam valve. The outlet of the high-pressure suspended main steam valve is connected to the main steam inlet of the high-parameter back-pressure saturated steam turbine. The high-parameter back-pressure saturated steam turbine is driven by the first generator. The exhaust outlets of the high-parameter back-pressure saturated steam turbine and the heat pipe boiler are both connected to the low-pressure steam network.

[0009] Furthermore, the second power generation structure includes a low-parameter, large-capacity saturated steam turbine and a second generator, as well as a low-pressure steam-water separator, a heater, and a floor-mounted main steam valve shared by the two second power generation structures. The main steam inlet of the low-pressure steam-water separator is connected to the steam outlet of the first power generation structure, the main steam outlet of the low-pressure steam-water separator is connected to the inlet of the heater, the main steam outlet of the heater is connected to the main steam inlet of the floor-mounted main steam valve, the main steam outlet of the floor-mounted main steam valve is connected to the steam inlet of the second proportional regulating valve, the two steam outlets of the second proportional regulating valve are respectively connected to the main steam inlets of the two low-parameter, large-capacity saturated steam turbines, and the low-parameter, large-capacity saturated steam turbines are connected to the second generator.

[0010] Furthermore, the desuperheating and pressure reducing device includes an inner tube and an outer tube. The high-parameter, high-flow-rate saturated steam expands through the pores on the surface of the inner tube and enters the outer tube. The outer tube is equipped with a desuperheating structure, and the water inlet end of the desuperheating structure extends through the outer tube and the outer shell of the desuperheating and pressure reducing device.

[0011] A control method for a high-parameter, high-flow-rate saturated steam cascade waste heat recovery system is proposed, which utilizes the high-parameter, high-flow-rate saturated steam cascade waste heat recovery system. When the first power generation structure is shut down: The first steam proportional regulating component controls the high-parameter, high-flow-rate saturated steam generated by the high-pressure steam source to be sent into the desuperheating and pressure-reducing component; the second steam proportional regulating component controls the flow of the two sets of second power generation structures to be balanced, and then sends the desuperheated and pressure-reduced steam into the two sets of second power generation structures to generate electricity. When one of the second power generation structures shuts down: the control of the second steam proportional adjustment component will send all the low-pressure saturated steam generated by the first power generation structure into the second power generation structure that has not shut down to generate electricity; When the high-pressure steam source generates high-parameter, high-flow-rate saturated steam that exceeds the power generation capacity of the first power generation structure: control the first steam proportional adjustment component so that the excess high-parameter, high-flow-rate saturated steam is supplied to the second power generation structure after passing through the de-cooling and de-pressure reduction component; control the second steam proportional adjustment component so that the flow of the two sets of second power generation structures is balanced, and then send the de-cooled and de-pressure reduced steam into the two sets of second power generation structures for power generation.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Saturated steam generated by the waste heat boiler undergoes primary dehumidification before entering the back-pressure turbine for expansion and power generation. The steam then enters the low-pressure steam network, which further distributes it to the external network for production, domestic use, and deaeration. The remaining steam undergoes secondary dehumidification before entering a pure condensing saturated steam turbine for power generation. This system embodies the principle of "on-demand allocation and tiered utilization," resulting in good tiered utilization efficiency and maximizing the utilization efficiency of waste heat resources. 2. The system can shut down any power generation structure for maintenance through the control of the first and second steam proportional regulation components, while maintaining power generation without interruption. This provides high stability for the tiered utilization of the system, creating a stable heating environment and enabling the system to supply heat for different types of heat demands. When the high-pressure steam source fluctuates or high-parameter, high-flow-rate saturated steam is added, the first steam proportional regulation component is controlled to allow the excess steam to pass through the desuperheating and pressure-reducing components, so that the two sets of second power generation structures can jointly carry the excess steam to generate electricity. This improves the system's ability to adapt to changes and is less affected by fluctuations in the high-pressure steam source.

[0013] 3. The low-pressure steam pipeline network enables the collection, stabilization, and on-demand distribution of low-pressure steam. It can regulate the flow distribution of low-pressure steam based on the economic comparison between steam power generation and external steam supply, thereby optimizing the utilization of low-pressure steam to obtain the maximum benefit. 4. The installation of high-pressure steam-water separator, low-pressure steam-water separator and heater ensures the quality of saturated steam entering the turbine unit, providing a reliable guarantee for the safe and stable operation of the system.

[0014] 5. The waste heat power generation system is coupled with a closed-loop circulating water heating system. During the winter heating season, the condenser can operate at a low vacuum to meet the heating needs of the circulating water, thereby further improving the energy utilization rate of the entire system. Attached Figure Description

[0015] The present invention will now be described in further detail with reference to the accompanying drawings.

[0016] Figure 1 Connection diagram of the system in Embodiment 1 of the present invention; Figure 2 : A schematic diagram of the de-cooling and pressure-reducing device in the axial direction of Embodiment 1 of the present invention; Figure 3 : A cross-sectional view of the de-cooling and de-pressure reducing device in Embodiment 1 of the present invention; The components include: 1. High-pressure steam-water separator; 2. High-pressure suspended main steam valve; 3. High-parameter back-pressure saturated steam turbine; 4. First generator; 5. Desuperheating and pressure-reducing device; 6. Low-pressure steam-water separator; 7. Heater; 8. Floor-mounted main steam valve; 9. Low-parameter large-capacity saturated steam turbine; 10. Second generator; 11. Condenser; 12. Cooling tower; 13. Heat exchange station; 14. Heat user; 15. Condensate pump; 16. Shaft seal heater; 17. Deaerator; 18. Water pump; 19. Waste heat boiler; 20. Heat pipe boiler; 22. Industrial steam user unit; 23. Domestic steam user unit; 24. First proportional regulating valve; 25. Second proportional regulating valve; 26. Four-way connector; 27. Circulating water pump; 210. Steam passage for power generation; 211. Steam passage for industrial use; 212. Steam passage for domestic use. 213. Bypass passage; 214. Deoxygenation steam passage; 51. Inner pipe; 52. Outer pipe; 53. Cooling structure. Detailed Implementation

[0017] To better understand the present invention, the content of the invention is further clearly illustrated below with reference to embodiments and accompanying drawings. However, the scope of protection of the present invention is not limited to the embodiments described below. Numerous specific details are set forth in the following description to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details.

[0018] Example 1: See Figure 1 This embodiment of a high-parameter, high-flow-rate saturated steam cascade utilization waste heat recovery system includes: A high- and low-pressure steam power generation system includes a first power generation structure and two sets of second power generation structures. The first power generation structure generates power using high-parameter, high-flow-rate saturated steam from the high-pressure steam source and produces low-pressure saturated steam. The second power generation structures generate power using the low-pressure saturated steam and discharge steam. By generating power through the first power generation from the high-parameter, high-flow-rate saturated steam and the second power generation from the low-pressure saturated steam, the steam generates a high amount of power, and the energy recovery rate of the high-pressure steam source is high. The system also includes a first steam proportional control component, a second steam proportional control component, and a desuperheating and pressure reducing component. The desuperheating and pressure reducing component is connected in parallel with the first power generation structure. It converts the high-parameter, high-flow-rate saturated steam into low-pressure saturated steam. The first steam proportional control component adjusts the proportion of high-parameter, high-flow-rate saturated steam entering the first power generation structure and the desuperheating and pressure reducing component, allowing the desuperheating and pressure reducing component to divert steam from the first power generation structure or to shut down the first power generation structure for maintenance. When maintenance is required on one of the second power generation structures, the second steam proportional control component controls the steam to no longer enter the second power generation structure to be maintained, thus ensuring the first... The first power generation structure and a set of second power generation structures complete the power generation task. When the high-pressure steam source fluctuates or high-parameter, high-flow-rate saturated steam is added, the first steam proportional regulation component is controlled to allow the excess steam to pass through the desuperheating and pressure-reducing component, so that the two sets of second power generation structures can jointly carry the excess steam to generate electricity, improving the system's adaptability to changes and making it less affected by high-pressure steam source fluctuations. The second steam proportional regulation component is used to regulate the proportion of low-pressure saturated steam flowing into the two sets of second power generation structures, so that when the first power generation structure is shut down, the two sets of second power generation structures can jointly carry the power generation, or when the first power generation structure is running, any second power generation structure can be shut down. When the first power generation structure needs maintenance, the first steam proportional regulation component is controlled to prevent steam from entering the first power generation structure. At this time, the steam is depressurized by the desuperheating and pressure-reducing component and then enters the second steam proportional regulation component. The second steam proportional regulation component diverts the steam to the two sets of second power generation structures for power generation, avoiding excessive load on one set of second power generation structures. The system can shut down any power generation structure for maintenance through the control of the first and second steam proportional regulation components, while not interrupting power generation. It also includes a condensation circulation system, which is used to transfer the steam discharged after the second power generation and to condense the steam into circulating water. The heat is then used to transport the cooled circulating water to a high-pressure steam source for reheating and reuse; see also Figure 1The condensing circulation system includes a condenser 11, a cooling tower 12, a heat exchange station 13, a heat user 14, a condensate pump 15, a shaft seal heater 16, and a deaerator 17. The main steam outlet of the second power generation structure is connected to the condenser 11. In this embodiment, the condenser 11 is specifically a condensing heat exchanger. The circulating water outlet of the condenser 11 is connected to a circulating water pump 27, which provides power for the flow of circulating water. The condenser 11 has two sets of circulating water outlets; one set is connected to the cooling tower 12, and the other set is connected to the cooling tower 13. The circulating water from condenser 11 flows back to cooling tower 12 via heat exchange station 13 and user 14. The outlet of cooling tower 12 is connected to condenser 11. The residual heat after the gas from the second power generation structure liquefies is utilized by user 14 after heat exchange with the circulating water. The circulating water, after being cooled by cooling tower 12, returns to condenser 11 for heat exchange. The condensate outlet of condenser 11 is connected to the inlet of condensate pump 15, and the outlet of condensate pump 15 is connected to the inlet of shaft seal heater 16. Shaft seal heater 16 utilizes the steam leakage from the shaft seal for heat exchange. Heating condensate and recovering steam leakage from the shaft seal reduces steam leakage and heat loss, improving heat utilization. The outlet of the shaft seal heater 16 is connected to the inlet of the deaerator 17. After the steam liquefaction process, the condensate is cooled by heat exchange with the circulating water in the cooling tower 12. The condensate is then sent to the shaft seal heater 16 and the deaerator 17 for deoxygenation. The outlet of the deaerator 17 is connected to the inlet of the feedwater pump 18. The steam used by the deaerator 17 comes from the low-pressure steam network. The outlet of the feedwater pump 18 is connected to the inlet of the heat pipe boiler 20. After liquefaction, the condensate is pumped back to the waste heat boiler 19 and heat pipe boiler 20 via feedwater pump 18. The heat pipe boiler 20 heats the condensate to generate steam, which is then used for the low-pressure steam network. The condensate produced by the condenser 11 is deoxygenated by the condensate pump 15, shaft seal heater 16, and deaerator 17, and then pumped back to the waste heat boiler 19 and heat pipe boiler 20 via feedwater pump 18. This keeps the entire waste heat power generation system in a closed-loop steam-water cycle. The condensation cycle system as a whole embodies the idea of ​​"distribution on demand and tiered utilization", which can maximize the utilization efficiency of waste heat resources. It also includes a low-pressure steam network, which receives low-pressure saturated steam and supplies it to production, domestic use, and condensation / deaeration applications; see [link / reference] Figure 1 High-parameter, high-flow-rate saturated steam, after being used for the first power generation, produces low-pressure saturated steam. Part of this steam is combined with the steam generated by the heat pipe boiler 20 and enters the low-pressure steam network. The low-pressure steam network includes a bypass channel 213, a power generation steam channel 210, and a deaeration steam channel 214. It also includes an industrial steam channel 211, a domestic steam channel 212, and a bypass channel 213. The low-pressure steam network is used to redistribute the low-pressure saturated steam into the power generation steam channel 210, the industrial steam channel 211, the domestic steam channel 212, the bypass channel 213, and the deaeration steam channel 214, thereby increasing the utilization scenarios of the steam.

[0019] See Figure 1 The high-pressure steam source includes a waste heat boiler 19. The first steam proportional control assembly includes a first proportional control valve 24, and the second steam proportional control assembly includes a second proportional control valve 25. A four-way connector 26 connects to the steam outlet of the first power generation structure. The desuperheating and pressure-reducing assembly includes a desuperheating and pressure-reducing device 5. Both the first proportional control valve 24 and the second proportional control valve 25 include a steam inlet and two sets of steam outlets. The steam inlet of the first proportional control valve 24 is connected to the waste heat boiler 19, and the two sets of steam outlets of the first proportional control valve 24 are respectively connected to the first power generation structure and the desuperheating and pressure-reducing device 5. The temperature and pressure reducing device 5 is connected. The first proportional regulating valve 24 can regulate the flow ratio through the first power generation structure and the temperature and pressure reducing device 5, or make the steam flow completely to either the first power generation structure or the temperature and pressure reducing device 5. The steam outlet of the first power generation structure and the temperature and pressure reducing device 5 is connected to the air inlet of the four-way connector 26. The steam inlet of the second proportional regulating valve 25 is connected to one of the steam outlets of the four-way connector 26. The steam outlet of the second proportional regulating valve 25 is connected to two sets of second power generation structures respectively. The other steam outlet of the four-way connector 26 is connected to the air inlet of the low-pressure steam pipeline network.

[0020] See Figure 1 The first power generation structure includes a high-pressure steam-water separator 1 and a high-pressure suspended main steam valve 2, as well as a high-parameter back-pressure saturated steam turbine 3 and a first generator 4. The steam inlet of the high-pressure steam-water separator 1 is connected to the high-parameter, high-flow-rate saturated steam outlet of the waste heat boiler 19. The steam turbine 3 receives the high-parameter, high-flow-rate saturated steam generated by the waste heat boiler 19 and generates electricity through the first generator 4. After power generation, low-pressure saturated steam is produced and discharged. The outlet of the high-pressure steam-water separator 1 is connected to the main steam inlet of the high-pressure suspended main steam valve 2. After removing moisture from the high-parameter, high-flow-rate saturated steam, the outlet of the high-pressure suspended main steam valve 2 is connected to the main steam inlet of the high-parameter back-pressure saturated steam turbine 3. The high-parameter back-pressure saturated steam turbine 3 is connected to the first generator 4 via a drive. The high-parameter back-pressure saturated steam turbine 3 directly drives the first generator 4 to generate electricity through a rigid coupling. The unit type of the high-parameter back-pressure saturated steam turbine 3 is a back-pressure generator and an impulse saturated steam turbine. The exhaust outlets of both the high-parameter back-pressure saturated steam turbine 3 and the heat pipe boiler 20 are connected to the low-pressure steam pipeline network.

[0021] See Figure 1The second power generation structure includes a low-parameter, large-capacity saturated steam turbine 9 and a second generator 10. It also includes a low-pressure steam-water separator 6, a heater 7, and a floor-mounted main steam valve 8, shared by both second power generation structures. The steam after desuperheating and depressurization by the desuperheating and depressurization device 5 has a high humidity. The main steam inlet of the low-pressure steam-water separator 6 is connected to the steam outlet of the first power generation structure. The steam-water separator 6 separates the depressurized steam into steam and water. The main steam outlet of the low-pressure steam-water separator 6 is connected to the inlet of the heater 7. The main steam outlet of the heater 7 is connected to the main steam inlet of the floor-mounted main steam valve 8. The pressure is increased by heating the steam in the heater 7. The steam then enters the low-parameter, large-capacity saturated steam turbine 9 through the floor-mounted main steam valve 8. The main steam outlet of the floor-mounted main steam valve 8 is connected to the steam inlet of the second proportional regulating valve 25. The two steam outlets of the second proportional regulating valve 25 are respectively connected to the main steam inlets of the two sets of low-parameter, large-capacity saturated steam turbines 9. The low-parameter, large-capacity saturated steam turbine 9 is connected to the second generator 10 via a drive. The low-parameter, large-capacity saturated steam turbine 9 is directly connected to the second generator 10 via a rigid coupling. The low-pressure saturated steam drives the second generator 10 to generate electricity through the low-parameter, large-capacity saturated steam turbine 9, and then discharges steam after generating electricity.

[0022] See Figure 2-3 The desuperheating and pressure reducing device 5 includes an inner tube 51 and an outer tube 52. When steam passes through the pores on the surface of the inner tube 51, it expands and enters the outer tube 52. The outer tube 52 is equipped with a desuperheating structure 53. The water inlet end of the desuperheating structure 53 extends out of the outer tube 52 and the outer shell of the desuperheating and pressure reducing device 5. The liquid enters the outer tube 52 through the desuperheating structure 53 and is sprayed out by the nozzle of the desuperheating structure 53. After contacting the high-temperature steam, it vaporizes and is discharged from the outer tube 52 with the steam.

[0023] Beneficial effects: 1. Waste heat boiler 19 generates saturated steam at 4MPa–6MPa. After primary dehumidification, the steam enters the back-pressure turbine for expansion and work, becoming saturated steam at 0.7MPa–0.9MPa. This steam then enters the low-pressure steam network, which further distributes the low-pressure steam to the external network for production, domestic use, and deaeration. The remaining steam undergoes secondary dehumidification before entering a pure condensing saturated steam turbine for power generation. This embodies the principle of "distribution on demand and tiered utilization," maximizing the efficiency of waste heat resource utilization.

[0024] 2. When maintenance of the first power generation structure is required, the first steam proportional regulation component is controlled to prevent steam from entering the first power generation structure. At this time, the steam is depressurized by the desuperheating and depressurization component and then enters the second steam proportional regulation component. The second steam proportional regulation component diverts the steam to two groups of second power generation structures for power generation, avoiding excessive load on one group of second power generation structures. When maintenance of one group of second power generation structures is required, the second steam proportional regulation component controls the steam to prevent it from entering the second power generation structure to be maintained, allowing the first power generation structure and one group of second power generation structures to complete their power generation tasks. This system can shut down any power generation structure for maintenance through the control of the first and second steam proportional regulation components, while not interrupting power generation. This provides high stability for the tiered utilization of the system, creating a stable heating environment, and enabling the system to provide heating for different types of heat demand. When the high-pressure steam source fluctuates or high-parameter, high-flow-rate saturated steam is added, the first steam proportional regulation component is controlled to allow the excess steam to pass through the desuperheating and depressurization component, allowing both groups of second power generation structures to share the excess steam for power generation. This improves the system's adaptability to changes and reduces the impact of high-pressure steam source fluctuations.

[0025] 3. Waste heat boiler 19 generates saturated steam at 4MPa–6MPa. After primary dehumidification, the steam enters the back-pressure turbine, expands to perform work, and becomes saturated steam at 0.7MPa–0.9MPa, which then enters the low-pressure steam network. The low-pressure steam network further distributes the low-pressure steam to the external network for production, domestic use, and deaeration. The remaining steam undergoes secondary dehumidification before entering the pure condensing saturated steam turbine for power generation. This embodies the concept of "distribution on demand and tiered utilization," maximizing the efficiency of waste heat resource utilization.

[0026] 4. In the closed-loop circulating water heating system, the condenser 11 can operate at a low vacuum during the winter heating season to meet the heating needs of the circulating water, thereby further improving the energy utilization rate of the entire system.

[0027] 5. The installation of high-pressure steam-water separator 1, low-pressure steam-water separator 6 and heater 7 ensures the quality of saturated steam entering the turbine unit, providing a reliable guarantee for the safe and stable operation of the system; 6. High-pressure steam-water separator 1, low-pressure steam-water separator 6, back-pressure saturated steam turbine, condensate water from condensing saturated steam turbine, return water from external steam supply and domestic steam, and steam for power generation are all condensed into condensate after passing through condenser 11. All of this water is then recycled into deaerator 17, and after thermal deaeration, it returns to waste heat boiler 19 and heat pipe boiler 20. This achieves a closed-loop steam-water circulation in the entire saturated steam waste heat power generation system. The working fluid in this waste heat power generation system is saturated steam. The system generates a large amount of condensate, which is demineralized water with a cost of 20-30 yuan / ton. Effective recovery of the condensate generated by the entire system can effectively control the economic cost of the entire system.

[0028] Example 2: A control method for a high-parameter, high-flow-rate saturated steam cascade waste heat recovery system, used to control the high-parameter, high-flow-rate saturated steam cascade waste heat recovery system in Example 1. When the first power generation structure is shut down: the first steam proportional adjustment component is controlled to send all the high-parameter, high-flow-rate saturated steam generated by the high-pressure steam source into the desuperheating and pressure-reducing component; the second steam proportional adjustment component is controlled to balance the flow of the two sets of second power generation structures and then send the desuperheated and pressure-reduced steam into the two sets of second power generation structures for power generation, so as to realize the power generation task of the first power generation structure shutdown maintenance work, so that the entire power generation system has a better uninterrupted operation effect; When one of the second power generation structures is shut down: the second steam proportional regulation component is controlled to send all the low-pressure saturated steam generated by the first power generation structure to the second power generation structure that is not shut down, so as to ensure that the power generation system can operate normally when any power generation structure is shut down for maintenance, which facilitates the maintenance of the power generation structure. When the high-pressure steam source generates high-parameter, high-flow-rate saturated steam exceeding the power generation capacity of the first power generation structure: the first steam proportional regulation component is controlled so that the excess high-parameter, high-flow-rate saturated steam is supplied to the second power generation structure after passing through the de-cooling and de-pressure reducing component; the second steam proportional regulation component is controlled so that the flow of the two sets of second power generation structures is balanced, and the de-cooled and de-pressure reduced steam is sent into the two sets of second power generation structures for power generation. By balancing the boiler steam through de-cooling and de-pressure reducing, the boiler's production capacity can be fully utilized, and the entire power generation system can have a certain adaptability and adjustment capability when the steam fluctuates.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A high-parameter, high-flow-rate saturated steam cascade waste heat recovery system, characterized in that, Including a high-pressure steam source, and also: A high- and low-pressure steam power generation system includes a first power generation structure and two sets of second power generation structures. The first power generation structure generates power and produces low-pressure saturated steam using high-parameter, high-flow-rate saturated steam from a high-pressure steam source. The second power generation structures generate power and discharge steam using the low-pressure saturated steam. The system also includes a first steam proportioning component, a second steam proportioning component, and a desuperheating and pressure reducing component. The desuperheating and pressure reducing component is connected in parallel with the first power generation structure and converts the high-parameter, high-flow-rate saturated steam into low-pressure saturated steam. The first steam proportioning component adjusts the proportion of the high-parameter, high-flow-rate saturated steam entering the first power generation structure and the desuperheating and pressure reducing component. The second steam proportioning component adjusts the proportion of low-pressure saturated steam flowing into the two sets of second power generation structures. A low-pressure steam pipeline network is used to transmit the low-pressure saturated steam and to supply the low-pressure saturated steam to production, domestic use, and deoxygenation. A condensation circulation system is provided, which is used to receive steam discharged from the second power generation structure, condense the steam to form circulating water, and transport the cooled circulating water, which has been used to utilize heat, to the high-pressure steam source. The high-pressure steam source includes a waste heat boiler (19), the first steam proportional adjustment component includes a first proportional adjustment valve (24), the second steam proportional adjustment component includes a second proportional adjustment valve (25), the steam outlet of the first power generation structure is connected to a four-way connector (26), the de-heating and pressure reducing component includes a de-heating and pressure reducing device (5), both the first proportional adjustment valve (24) and the second proportional adjustment valve (25) include a steam inlet and two sets of steam outlets, the steam inlet of the first proportional adjustment valve (24) is connected to the waste heat boiler (19), the two sets of steam outlets of the first proportional adjustment valve (24) are respectively connected to the first power generation structure and the de-heating and pressure reducing device (5), the steam outlets of the first power generation structure and the de-heating and pressure reducing device (5) are connected to the air inlet of the four-way connector (26), the steam inlet of the second proportional adjustment valve (25) is connected to the steam outlet of the four-way connector (26), and the steam outlet of the second proportional adjustment valve (25) is respectively connected to two sets of the second power generation structure.

2. The high-parameter, high-flow-rate saturated steam cascade waste heat recovery system as described in claim 1, characterized in that, The condensation circulation system includes a condenser (11), a cooling tower (12), a heat exchange station (13), a heat user (14), a condensate pump (15), a shaft seal heater (16), a deaerator (17), and a heat pipe boiler (20). The main steam outlet of the second power generation structure is connected to the condenser (11). The condenser (11) has two sets of circulating water outlets. One set of the circulating water outlets of the condenser (11) is connected to the cooling tower (12), and the other set of the circulating water outlets of the condenser (11) is connected to the heat exchange station (13), the heat user (14), and the cooling tower (12) in sequence. The outlet of the cooling tower (12) is connected to the condenser (11). The condensate outlet of the condenser (11) is connected to the condensate pump (15), the shaft seal heater (16), the deaerator (17), the feed water pump (18), and the heat pipe boiler (20) in sequence. The heat pipe boiler (20) heats and generates steam, which is then used for gas supply in the low-pressure steam network.

3. The high-parameter, high-flow-rate saturated steam cascade waste heat recovery system as described in claim 2, characterized in that, The low-pressure steam network includes a bypass channel (213), a power generation steam channel (210), and a deoxygenation steam channel (214), as well as an industrial steam channel (211), a domestic steam channel (212), and a bypass channel (213). The low-pressure steam network is used to redistribute low-pressure saturated steam into the power generation steam channel (210), the industrial steam channel (211), the domestic steam channel (212), the bypass channel (213), and the deoxygenation steam channel (214).

4. The high-parameter, high-flow-rate saturated steam cascade waste heat recovery system as described in claim 1, characterized in that, The first power generation structure includes a high-pressure steam-water separator (1), a high-pressure suspended main steam valve (2), a high-parameter back-pressure saturated steam turbine (3), and a first generator (4). The steam inlet of the high-pressure steam-water separator (1) is connected to the high-parameter, high-flow-rate saturated steam outlet of the waste heat boiler (19). The outlet of the high-pressure steam-water separator (1) is connected to the main steam inlet of the high-pressure suspended main steam valve (2). The outlet of the high-pressure suspended main steam valve (2) is connected to the main steam inlet of the high-parameter back-pressure saturated steam turbine (3). The high-parameter back-pressure saturated steam turbine (3) is connected to the first generator (4) via a drive. The exhaust outlets of the high-parameter back-pressure saturated steam turbine (3) and the heat pipe boiler (20) are both connected to the low-pressure steam network.

5. The high-parameter, high-flow-rate saturated steam cascade waste heat recovery system as described in claim 4, characterized in that, The second power generation structure includes a low-parameter large-capacity saturated steam turbine (9) and a second generator (10), and also includes a low-pressure steam-water separator (6), a heater (7) and a floor-mounted main steam valve (8) shared by the two second power generation structures. The main steam inlet of the low-pressure steam-water separator (6) is connected to the steam outlet of the first power generation structure. The main steam outlet of the low-pressure steam-water separator (6) is connected to the inlet of the heater (7). The main steam outlet of the heater (7) is connected to the main steam inlet of the floor-mounted main steam valve (8). The main steam outlet of the floor-mounted main steam valve (8) is connected to the steam inlet of the second proportional regulating valve (25). The two steam outlets of the second proportional regulating valve (25) are respectively connected to the main steam inlets of the two low-parameter large-capacity saturated steam turbines (9). The low-parameter large-capacity saturated steam turbine (9) is driven by the second generator (10).

6. The high-parameter, high-flow-rate saturated steam cascade waste heat recovery system as described in claim 1, characterized in that, The de-heating and pressure reducing device (5) includes an inner tube (51) and an outer tube (52). The high-parameter, high-flow-rate saturated steam expands through the pores on the surface of the inner tube (51) and enters the outer tube (52). The outer tube (52) is equipped with a de-heating structure (53). The water inlet end of the de-heating structure (53) extends out of the outer tube (52) and the outer shell of the de-heating and pressure reducing device (5).

7. A control method for a high-parameter, high-flow-rate saturated steam cascade utilization waste heat recovery system, used to control the high-parameter, high-flow-rate saturated steam cascade utilization waste heat recovery system as described in any one of claims 1-6, characterized in that, include: When the first power generation structure is shut down: the first steam proportional regulating component controls the high-parameter, high-flow-rate saturated steam generated by the high-pressure steam source to be sent into the de-cooling and pressure-reducing component; the second steam proportional regulating component controls the flow of the two sets of second power generation structures to be balanced, and then sends the de-cooled and pressure-reduced steam into the two sets of second power generation structures to generate electricity. When one of the second power generation structures shuts down: the control of the second steam proportional adjustment component sends all the low-pressure saturated steam generated by the first power generation structure to the second power generation structure that has not shut down for power generation. When the high-pressure steam source generates high-parameter, high-flow-rate saturated steam that exceeds the power generation capacity of the first power generation structure: control the first steam proportional adjustment component so that the excess high-parameter, high-flow-rate saturated steam is supplied to the second power generation structure after passing through the de-cooling and de-pressure reduction component; control the second steam proportional adjustment component so that the flow of the two sets of second power generation structures is balanced, and then send the de-cooled and de-pressure reduced steam into the two sets of second power generation structures for power generation.

Images