Waste heat power generation system

Abstract

The utility model discloses a waste heat power generation system which comprises a waste heat boiler, a first superheater, a low-temperature and low-pressure steam turbine, a first generator, a gas generator set, a medium-temperature and medium-pressure steam turbine, a first temperature and pressure reduction unit, a waste heat recovery heat exchanger, a phase change heat storage tank, a steam buffer tank and a second temperature and pressure reduction unit. The gas generator set at least comprises a gas boiler and a second superheater, the input end of the first temperature and pressure reduction unit is connected with a medium-temperature medium-pressure pipeline, a first output interface of the first temperature and pressure reduction unit is connected with a medium-temperature medium-pressure steam turbine, and a second output interface is connected with the high-temperature end of the waste heat recovery heat exchanger; therefore, medium-temperature and medium-pressure steam generated by the gas generator set can be flexibly distributed to the medium-temperature and medium-pressure steam turbine to do work and generate power through the first temperature and pressure reduction unit according to actual requirements, or is conveyed to the high-temperature end of the waste heat recovery heat exchanger through the second output connector, heat is further recovered, and the comprehensive utilization rate of energy is remarkably increased.

Description

Technical Field

[0001] This utility model relates to the field of waste heat power generation systems, and in particular to a waste heat power generation system. Background Technology

[0002] In energy-intensive industries such as steel and metallurgy, sintering waste heat power generation technology is widely used to recover waste heat resources from the production process.

[0003] Traditional waste heat power generation systems typically use low-temperature, low-pressure steam to drive steam turbines for power generation. However, due to the instability of the sintering process, the steam parameters (temperature, pressure, and flow rate) generated by the waste heat boiler fluctuate significantly, leading to frequent start-ups and shutdowns of the generator set, which seriously affects operating efficiency and economy.

[0004] In the existing technology, some solutions attempt to supplement steam by gas generator sets and use desuperheating and depressurization devices to adjust the medium-temperature and medium-pressure steam to low-temperature and low-pressure parameters before supplying it to the waste heat power generation system. However, such solutions still have the following problems: (1) large energy loss: its single-stage desuperheating and depressurization process leads to a significant reduction in steam enthalpy and low thermal energy utilization rate; (2) insufficient waste heat recovery: the waste heat is not deeply utilized, such as boiler feedwater preheating and steam energy storage, resulting in low overall energy efficiency; (3) lack of bidirectional coupling: the gas power generation and waste heat power generation systems operate independently and cannot serve as backups for each other under extreme working conditions.

[0005] Therefore, a new technical solution needs to be researched to address the above problems. Utility Model Content

[0006] In view of this, the present invention addresses the deficiencies of the existing technology, and its main objective is to provide a waste heat power generation system. Through the design of its various components, the medium-temperature, medium-pressure steam generated by the gas generator set can be flexibly distributed to the medium-temperature, medium-pressure steam turbine for power generation via the first desuperheating and pressure-reducing unit, or transported to the high-temperature end of the waste heat recovery heat exchanger via the second output interface for further heat recovery. Compared with traditional independently operating gas generator sets and waste heat power generation systems, this significantly improves the overall energy utilization rate. Secondly, the phase change heat storage tank can store excess steam heat energy output from the first superheater. When the waste heat generation is insufficient, steam is released to the steam buffer tank. The steam buffer tank, through the flexible allocation of the first and second output ports, ensures a stable steam supply to the low-temperature, low-pressure steam turbine, enabling the waste heat power generation set to operate continuously and stably.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A waste heat power generation system includes a waste heat boiler, a first superheater, a low-temperature and low-pressure steam turbine, a first generator, a gas generator set, and a medium-temperature and medium-pressure steam turbine. The waste heat boiler is connected to the first superheater, the output end of the first superheater is connected to the low-temperature and low-pressure steam turbine through a low-temperature and low-pressure pipeline, and the output end of the low-temperature and low-pressure steam turbine is connected to the first generator.

[0009] The waste heat power generation system further includes a first de-temperature and pressure reduction unit, a waste heat recovery heat exchanger, a phase change heat storage tank, a steam buffer tank, and a second de-temperature and pressure reduction unit; the first de-temperature and pressure reduction unit includes a first output interface and a second output interface.

[0010] The gas generator set includes at least a gas boiler and a second superheater. The output end of the gas boiler is connected to the input end of the second superheater. The output end of the second superheater is connected to the other input end of the first desuperheating and depressurization unit through a medium-temperature and medium-pressure pipeline.

[0011] The waste heat recovery heat exchanger includes a high-temperature end and a low-temperature end; the output end of the waste heat recovery heat exchanger is connected to an input end of the second de-temperature and pressure reduction unit.

[0012] The input end of the first de-temperature and pressure reducing unit is connected to the medium-temperature and medium-pressure pipeline, its first output interface is connected to the medium-temperature and medium-pressure steam turbine, and its second output interface is connected to the high-temperature end of the waste heat recovery heat exchanger.

[0013] The input end of the phase change thermal storage tank is connected to the output end of the first superheater, and the output end of the phase change thermal storage tank is connected to the input end of the steam buffer tank; the steam buffer tank is provided with a first output port and a second output port, the first output port of the steam buffer tank is connected to a low temperature and low pressure pipeline; the second output port of the steam buffer tank is connected to another input end of the second desuperheating and pressure reducing unit, and the output end of the second desuperheating and pressure reducing unit is connected to the low temperature and low pressure pipeline.

[0014] As a preferred embodiment, a regulating valve is also provided between the first outlet of the steam buffer tank and the low-temperature, low-pressure pipeline.

[0015] As a preferred embodiment, the gas generator set further includes a second boiler feedwater pump, a second boiler economizer, a second condensate pump, and a second condenser. The exhaust port of the medium-temperature and medium-pressure steam turbine is connected to the second condenser, and the second condenser is connected to the inlet of the second condensate pump. The low-temperature end inlet of the waste heat recovery heat exchanger is connected to the outlet pipeline of the second boiler feedwater pump, and the low-temperature end outlet of the waste heat recovery heat exchanger is connected to the inlet of the second boiler economizer.

[0016] As a preferred embodiment, a second shut-off valve is provided between the medium-temperature and medium-pressure pipeline and the input end of the first de-temperature and pressure reducing unit.

[0017] As a preferred embodiment, an interconnecting pipe is also provided between the exhaust port of the low-temperature, low-pressure steam turbine and the second condenser. A switching valve is installed on the interconnecting pipe. When the gas generator set fails, the low-temperature steam generated by waste heat power generation can assist in driving the medium-temperature, medium-pressure steam turbine through the interconnecting pipe, realizing bidirectional energy mutual assistance and improving system redundancy.

[0018] As a preferred embodiment, the output of the second de-temperature and pressure reducing unit is connected to a low-temperature and low-pressure pipeline via a one-way valve.

[0019] Compared with the prior art, this utility model has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution, it mainly improves the comprehensive energy utilization rate by coordinating the waste heat boiler, the first superheater, the low temperature and low pressure steam turbine, the first generator, the gas generator set, the medium temperature and medium pressure steam turbine, the gas generator set, the first desuperheating and pressure reducing unit, the waste heat recovery heat exchanger, the phase change heat storage tank, the steam buffer tank, and the second desuperheating and pressure reducing unit. In this way, the medium temperature and medium pressure steam generated by the gas generator set can be flexibly distributed to the medium temperature and medium pressure steam turbine to generate electricity according to actual needs through the first desuperheating and pressure reducing unit, or it can be sent to the high temperature end of the waste heat recovery heat exchanger through the second output interface to further recover heat. Compared with the traditional independently operating gas generator set and waste heat power generation system, this significantly improves the comprehensive energy utilization rate.

[0020] Secondly, the phase change heat storage tank can store the excess steam heat energy output by the first superheater. When the amount of waste heat generated is insufficient, steam is released to the steam buffer tank. The steam buffer tank ensures a stable steam supply to the low-temperature and low-pressure steam turbine through the flexible allocation of the first and second output ports, so that the waste heat power generation unit can operate continuously and stably.

[0021] Another method is to use a waste heat recovery heat exchanger to preheat the boiler feedwater during the de-cooling and de-pressure process, thereby improving the overall thermal efficiency of the system.

[0022] To more clearly illustrate the structural features and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0023] Figure 1 This is a control principle diagram of an embodiment of the present utility model;

[0024] Figure 2 This is another control principle diagram of an embodiment of the present utility model.

[0025] Explanation of reference numerals in the attached diagram:

[0026] 1. Waste heat boiler 2. First superheater

[0027] 3. Low-temperature, low-pressure steam turbine; 4. First generator

[0028] 5. Second generator; 6. Medium-temperature and medium-pressure steam turbine

[0029] 7. First condenser; 8. First condensate pump

[0030] 9. First deaerator; 10. First boiler feedwater pump

[0031] 11. Economizer for the first boiler 12. Gas boiler

[0032] 13. Second superheater 14. Medium-temperature and medium-pressure pipeline

[0033] 15. First desuperheating and pressure reduction unit; 16. Waste heat recovery heat exchanger

[0034] 161. High-temperature end 162. Low-temperature end

[0035] 17. Phase change thermal storage tank; 18. Steam buffer tank

[0036] 19. Second de-temperature and pressure reducing unit; 20. Switching valve

[0037] 21. First shut-off valve; 22. Pressure balancing valve

[0038] 23. Low-temperature and low-pressure pipelines 24. Control valves

[0039] 25. Interconnected pipelines 26. Second boiler feedwater pump

[0040] 27. Economizer for the second boiler 28. Second condensate pump

[0041] 29. Second condenser. Detailed Implementation

[0042] Please refer to Figures 1 to 2 The description shows the specific structure of an embodiment of the present invention.

[0043] In the description of this utility model, it should be noted that the directional terms such as "up", "down", "front", "back", "left", and "right" indicate the orientation and positional relationship based on the accompanying drawings or the orientation or positional relationship described during normal wear and use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this utility model.

[0044] A waste heat power generation system includes a waste heat boiler 1, a first superheater 2, a low-temperature and low-pressure steam turbine 3, a first generator 4, a gas generator set, and a medium-temperature and medium-pressure steam turbine 6, wherein the waste heat boiler 1 is connected to the first superheater 2.

[0045] The exhaust port of the low-temperature, low-pressure steam turbine 3 is connected to the first condenser 7, the first condenser 7 is connected to the inlet of the first condensate pump 8, the outlet of the first condensate pump 8 is connected to the inlet of the first deaerator 9, the outlet of the first deaerator 9 is connected to the inlet of the first boiler feedwater pump 10, and the outlet of the first boiler feedwater pump 10 is connected to the first boiler economizer 11. The output end of the second superheater 13 is connected to the medium-temperature, medium-pressure steam turbine 6 through the medium-temperature, medium-pressure pipeline 14, and the output end of the medium-temperature, medium-pressure steam turbine 6 is connected to the second generator 5.

[0046] The gas generator set includes at least a second generator, a gas boiler 12, and a second superheater 13. The output end of the gas boiler 12 is connected to the input end of the second superheater 13, and the output end of the second superheater 13 is connected to the other input end of the first de-heating and de-pressure unit 15 through a medium-temperature and medium-pressure pipeline 14.

[0047] The waste heat power generation system also includes a first de-temperature and pressure reducing unit 15, a waste heat recovery heat exchanger 16, a phase change heat storage tank 17, a steam buffer tank 18, and a second de-temperature and pressure reducing unit 19; the first de-temperature and pressure reducing unit 15 includes a first output interface and a second output interface; a pressure balancing valve 22 is also provided between the second de-temperature and pressure reducing unit 19 and the waste heat recovery heat exchanger 16.

[0048] The waste heat recovery heat exchanger 16 includes a high-temperature end 161 and a low-temperature end 162; the output end of the waste heat recovery heat exchanger 16 is connected to an input end of the second de-temperature and pressure reduction unit 19.

[0049] The input end of the first de-temperature and pressure reducing unit 15 is connected to the medium temperature and medium pressure pipeline 14, its first output interface is connected to the medium temperature and medium pressure steam turbine 6, and its second output interface is connected to the high temperature end 161 of the waste heat recovery heat exchanger 16.

[0050] Preferably, a second shut-off valve is provided between the medium-temperature and medium-pressure pipeline 14 and the input end of the first de-temperature and pressure reducing unit 15.

[0051] The input end of the phase change thermal storage tank 17 is connected to the output end of the first superheater 2, and the output end of the phase change thermal storage tank 17 is connected to the input end of the steam buffer tank 18; the steam buffer tank 18 is provided with a first output port and a second output port, the first output port of the steam buffer tank 18 is connected to the low temperature and low pressure pipeline 23; the second output port of the steam buffer tank 18 is connected to the other input end of the second de-temperature and pressure reducing unit 19, and the output end of the second de-temperature and pressure reducing unit 19 is connected to the low temperature and low pressure pipeline 23.

[0052] The output end of the first superheater 2 is connected to the low-temperature low-pressure steam turbine 3 through a low-temperature low-pressure pipeline 23, and the output end of the low-temperature low-pressure steam turbine 3 is connected to the first generator 4;

[0053] Preferably, a regulating valve 24 is also provided between the first output port of the steam buffer tank 18 and the low temperature and low pressure pipeline 23 to release the stored steam when the waste heat is insufficient, thereby improving the waste heat utilization rate and reducing start-up and shutdown losses by utilizing the high heat storage density of the phase change material.

[0054] Preferably, the gas generator set further includes a second boiler feedwater pump 26, a second boiler economizer 27, a second condensate pump 28, and a second condenser 29. The exhaust port of the medium-temperature and medium-pressure steam turbine 6 is connected to the second condenser 29, and the second condenser 29 is connected to the inlet of the second condensate pump 28. The inlet of the low-temperature end 162 of the waste heat recovery heat exchanger 16 is connected to the outlet pipeline of the second boiler feedwater pump 26, and the outlet of the low-temperature end 162 of the waste heat recovery heat exchanger 16 is connected to the inlet of the second boiler economizer 27. Waste heat is used to preheat the boiler feedwater. A first shut-off valve 21 is also provided between the output end of the waste heat recovery heat exchanger 16 and the low-temperature and low-pressure pipeline 23.

[0055] Preferably, an interconnecting pipe 25 is provided between the exhaust port of the low-temperature, low-pressure steam turbine 3 and the second condenser 29. A switching valve 20 is installed on the interconnecting pipe 25, along with a flow meter. When the gas generator set fails, the low-temperature steam from the waste heat power generation can assist in driving the medium-temperature, medium-pressure steam turbine 6 through the interconnecting pipe 25, achieving bidirectional energy mutual assistance and improving system redundancy. The gas generator set and the waste heat power generation system are coupled through the bidirectional interconnecting pipe 25. In the event of a failure on either side, the steam supply path can be quickly switched through the switching valve 20 to ensure uninterrupted power output. The priority regulating valve 24 of the steam buffer tank 18 can dynamically allocate the steam destination, prioritizing the needs of the steam turbine and avoiding frequent start-ups and shutdowns.

[0056] The interconnecting pipeline connects the exhaust port of the low-temperature, low-pressure steam turbine to the second condenser. Its function is to allow the steam turbine exhaust to flow to the second condenser under specific operating conditions. The switching valve is installed on the interconnecting pipeline to control the opening and closing of the pipeline or to switch the direction of steam flow. By operating the switching valve, the steam turbine exhaust can be flexibly introduced into the second condenser according to actual operating needs, so as to realize functions such as switching operation of the condenser, putting the standby condenser into use, and balancing the load between condensers, thereby improving the reliability and flexibility of the entire thermal system operation.

[0057] Preferably, the output end of the second de-temperature and pressure reducing unit 19 is connected to the low-temperature and low-pressure pipeline 23 through a one-way valve.

[0058] The key design feature of this utility model lies in the coordination between the waste heat boiler, the first superheater, the low-temperature and low-pressure steam turbine, the first generator, the gas generator set, the medium-temperature and medium-pressure steam turbine, the gas generator set, the first desuperheating and pressure reducing unit, the waste heat recovery heat exchanger, the phase change heat storage tank, the steam buffer tank, and the second desuperheating and pressure reducing unit. In this way, the medium-temperature and medium-pressure steam generated by the gas generator set can be flexibly distributed to the medium-temperature and medium-pressure steam turbine to generate electricity according to actual needs through the first desuperheating and pressure reducing unit, or it can be sent to the high-temperature end of the waste heat recovery heat exchanger through the second output interface to further recover heat. Compared with the traditional independently operating gas generator set and waste heat power generation system, this significantly improves the comprehensive energy utilization rate.

[0059] Secondly, the phase change heat storage tank can store the excess steam heat energy output by the first superheater. When the amount of waste heat generated is insufficient, steam is released to the steam buffer tank. The steam buffer tank ensures a stable steam supply to the low-temperature and low-pressure steam turbine through the flexible allocation of the first and second output ports, so that the waste heat power generation unit can operate continuously and stably.

[0060] Another method is to use a waste heat recovery heat exchanger to preheat the boiler feedwater during the de-cooling and de-pressure process, thereby improving the overall thermal efficiency of the system.

[0061] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A waste heat power generation system, comprising a waste heat boiler, a first superheater, a low-temperature, low-pressure steam turbine, a first generator, a gas generator set, and a medium-temperature, medium-pressure steam turbine, wherein the waste heat boiler is connected to the first superheater, the output end of the first superheater is connected to the low-temperature, low-pressure steam turbine via a low-temperature, low-pressure pipeline, and the output end of the low-temperature, low-pressure steam turbine is connected to the first generator; characterized in that: The waste heat power generation system further includes a first de-temperature and pressure reduction unit, a waste heat recovery heat exchanger, a phase change heat storage tank, a steam buffer tank, and a second de-temperature and pressure reduction unit; the first de-temperature and pressure reduction unit includes a first output interface and a second output interface. The gas generator set includes at least a gas boiler and a second superheater. The output end of the gas boiler is connected to the input end of the second superheater. The output end of the second superheater is connected to the other input end of the first desuperheating and depressurization unit through a medium-temperature and medium-pressure pipeline. The waste heat recovery heat exchanger includes a high-temperature end and a low-temperature end; the output end of the waste heat recovery heat exchanger is connected to an input end of the second de-temperature and pressure reduction unit. The input end of the first de-temperature and pressure reducing unit is connected to the medium-temperature and medium-pressure pipeline, its first output interface is connected to the medium-temperature and medium-pressure steam turbine, and its second output interface is connected to the high-temperature end of the waste heat recovery heat exchanger. The input end of the phase change thermal storage tank is connected to the output end of the first superheater, and the output end of the phase change thermal storage tank is connected to the input end of the steam buffer tank; the steam buffer tank is provided with a first output port and a second output port, the first output port of the steam buffer tank is connected to a low temperature and low pressure pipeline; the second output port of the steam buffer tank is connected to another input end of the second desuperheating and pressure reducing unit, and the output end of the second desuperheating and pressure reducing unit is connected to the low temperature and low pressure pipeline.

2. The waste heat power generation system of claim 1, wherein: A regulating valve is also installed between the first outlet of the steam buffer tank and the low-temperature, low-pressure pipeline.

3. The waste heat power generation system of claim 1, wherein: The gas generator set also includes a second boiler feedwater pump, a second boiler economizer, a second condensate pump, and a second condenser. The exhaust port of the medium-temperature and medium-pressure steam turbine is connected to the second condenser, and the second condenser is connected to the inlet of the second condensate pump. The low-temperature end inlet of the waste heat recovery heat exchanger is connected to the outlet pipeline of the second boiler feedwater pump, and the low-temperature end outlet of the waste heat recovery heat exchanger is connected to the inlet of the second boiler economizer.

4. The waste heat power generation system of claim 3, wherein: A second shut-off valve is installed between the medium-temperature and medium-pressure pipeline and the input end of the first de-temperature and pressure reducing unit.

5. The waste heat power generation system of claim 3, wherein: An interconnecting pipe is also provided between the exhaust port of the low-temperature, low-pressure steam turbine and the second condenser, and a switching valve is installed on the interconnecting pipe.

6. The waste heat power generation system of claim 1, wherein: The output of the second de-temperature and pressure reducing unit is connected to a low-temperature and low-pressure pipeline through a one-way valve.

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