Vapor compression waste heat utilization system
By generating flash steam at the lower part of the desulfurization tower and pressurized steam supply, combined with flue gas waste heat utilization and spraying device, the problem of steam supply parameters being limited by unit load in the prior art is solved, and efficient utilization of flexible steam supply and water resources is achieved.
Patent Information
- Application Number
- CN202510789059.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-13
- Publication Date
- 2025-07-29
AI Technical Summary
The existing industrial steam supply method is limited by the turbine load, which affects operating flexibility and increases the water use indicators of power plants, making it difficult to apply in water-scarce areas.
Flash steam is generated by using the high-temperature desulfurization slurry at the bottom of the desulfurization tower, and the steam supply is pressurized by a steam compressor, combined with the flue gas waste heat to utilize the heat exchanger and the spray device to recover the waste heat and water resources, and the steam supply parameters are not affected by the unit load.
It realizes steam supply that is not affected by unit load, recycles waste heat and precious water resources, reduces production costs, improves operating flexibility and water resource utilization efficiency.
Smart Images
Figure CN120385066A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of waste heat utilization in thermal power plants, and specifically to a steam compression waste heat utilization system. Background Art
[0002] This solution belongs to the technical field of waste heat utilization in thermal power plants. Currently, thermal power plants belong to energy-intensive industries, and their energy consumption and waste heat problems have always been the focus of energy conservation and emission reduction research. Waste heat utilization technology can convert the waste heat generated during the power generation process into reusable energy, which can not only significantly improve energy use efficiency but also help reduce the carbon emissions of thermal power plants. By recovering waste heat, thermal power plants can reduce their dependence on raw fuels, lower production costs, and contribute to environmental protection.
[0003] Existing industrial steam supply usually uses steam extraction from the steam turbine body for external steam supply or main steam desuperheating and pressure reduction for external steam supply. Steam extraction from the steam turbine body generally sets industrial steam extraction ports on the cylinder body for industrial steam use. Please refer to Figure 1 , or uses a certain stage of regenerative steam extraction for both industrial steam supply, or uses the cold reheat pipeline, hot reheat pipeline, and intermediate extraction pipeline for drilling steam extraction. Please refer to Figure 2 .
[0004] Existing industrial steam supply usually uses steam extraction from the steam turbine body for external steam supply. The units of large thermal power plants all operate at sliding pressure, that is, the steam supply parameters are restricted by the unit load. If the steam extraction parameters are to meet the user's requirements, the unit must operate above a certain load, which affects the operation flexibility. At the same time, industrial steam supply requires an increase in the power plant's water consumption index. In water-scarce areas, it is very difficult to increase the water consumption index. Summary of the Invention
[0005] The purpose of the present invention is to provide a steam compression waste heat utilization system that uses the waste heat of high-temperature water to generate flash steam, pressurizes the flash steam for industrial steam use, recovers waste heat and valuable water resources, generates economic benefits from external steam supply, the steam supply parameters are not affected by the unit load, and there is no need to increase the power plant's water consumption index.
[0006] The present invention is implemented as follows:
[0007] A steam compression waste heat utilization system includes a desulfurization tower. The lower part of the desulfurization tower is connected to the input end of a flash tank through a pipeline. The steam output end of the flash tank is connected to a steam compressor. The steam compressor is connected to a heat user through a pipeline. The water outlet end of the flash tank is connected to the upper part of the desulfurization tower.
[0008] Further, the steam compressor is driven by an electric motor or by a steam turbine.
[0009] Further, multiple steam compressors are used in cooperation to supply steam to heat users with different steam use parameters.
[0010] Furthermore, a spray device is provided on the upper portion of the desulfurization tower, the water outlet of the flash tank is communicated with the spray device, and a slurry pump is connected between the water outlet of the flash tank and the spray device.
[0011] Furthermore, the nozzle of the spraying device covers the cross section of the desulfurization tower.
[0012] Furthermore, the input end of the flash tank is connected to a flue gas waste heat utilization heat exchanger, which is arranged in the flue, and the high-temperature water output end of the flue gas waste heat utilization heat exchanger is connected to the input end of the flash tank, and the low-temperature water output end of the flash tank is connected to the low-temperature water input end of the flue gas waste heat utilization heat exchanger.
[0013] Furthermore, the flue gas waste heat utilization heat exchanger is an air-water heat exchanger.
[0014] Furthermore, the low-temperature water output end of the flash tank is connected to the low-temperature water input end of the flue gas waste heat utilization heat exchanger through a circulation pump.
[0015] Furthermore, an economizer is provided at the input end of the flue gas waste heat utilization heat exchanger, and an air preheater is provided between the economizer and the flue gas waste heat utilization heat exchanger.
[0016] Compared with the prior art, the present invention has the following beneficial effects:
[0017] In actual application, the high-temperature desulfurization slurry at the bottom of the desulfurization tower is taken out through a pipeline and sent to a flash tank. The steam generated in the flash tank is sent to a steam compressor. The steam compressor is driven by an electric motor or a steam turbine. The steam compressor pressurizes the flash steam and sends it to the heat user for industrial steam supply. The low-temperature desulfurization slurry output from the water outlet of the flash tank is sent back to the upper part of the desulfurization tower for heating and reuse. The present invention utilizes the waste heat of high-temperature water to generate flash steam, and pressurizes the flash steam to supply industrial steam, recovers waste heat and precious water resources, and generates economic benefits from external steam supply. The steam supply parameters are not affected by the unit load and there is no need to increase the water consumption index of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.
[0019] Figure 1 This is a schematic diagram of the existing technology of using steam turbine body to extract steam to supply industrial steam;
[0020] Figure 2 This is a schematic diagram of the existing technology of using punching holes in the middle exhaust, reheat cold section, and reheat hot section to extract steam for industrial use;
[0021] Figure 3 This is a schematic diagram of the process of utilizing desulfurized slurry to generate flash steam and compressing it to supply industrial steam;
[0022] Figure 4 This is a schematic flow chart of the present invention for utilizing high-temperature water generated by flue gas waste heat for flash evaporation and compression to supply industrial steam.
[0023] Reference numerals: desulfurization tower 1; flash tank 2; steam compressor 3; heat user 4; spray device 5; slurry pump 6; economizer 7; flue gas waste heat utilization heat exchanger 8; air preheater 9; circulation pump 10. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention for which protection is sought, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0025] See also Figure 3 A steam compression waste heat utilization system includes a desulfurization tower 1, the lower part of the desulfurization tower 1 is connected to the input end of the flash tank 2 through a pipeline, the steam output end of the flash tank 2 is connected to a steam compressor 3, and the steam compressor 3 is connected to a heat user 4 through a pipeline, and the water outlet end of the flash tank 2 is connected to the upper part of the desulfurization tower 1.
[0026] In practical applications, the high-temperature desulfurized slurry at the lower part of the desulfurization tower 1 is led out through a pipeline and sent to the flash tank 2. The steam generated by the flash tank 2 is sent into the steam compressor 3. The steam compressor 3 is driven by an electric motor or a steam turbine. After the steam compressor 3 pressurizes the flashed steam, it is sent to the heat user 4 for industrial steam use. The low-temperature desulfurized slurry output from the water outlet end of the flash tank 2 is sent back to the upper part of the desulfurization tower 1 for reheating and reuse. The present invention utilizes the waste heat of high-temperature water to generate flash steam, pressurizes the flash steam for industrial steam use, recovers the waste heat and valuable water resources, generates economic benefits from external steam supply, and the steam supply parameters are not affected by the unit load, and there is no need to increase the power plant water consumption index.
[0027] Please refer to Figure 3 , multiple sets of the steam compressors 3 are used in cooperation, and through series connection, parallel connection or other forms of combination, steam is supplied to heat users with different steam use parameters.
[0028] Please refer to Figure 3 , a spraying device 5 is arranged at the upper part of the desulfurization tower 1. The water outlet end of the flash tank 2 is communicated with the spraying device 5, and a slurry pump 6 is connected between the water outlet end of the flash tank 2 and the spraying device 5.
[0029] Under the driving action of the slurry pump 6, the low-temperature desulfurized slurry output from the water outlet end of the flash tank 2 is sent back to the spraying device 5 of the desulfurization tower 1. The nozzles of the spraying device 5 cover the cross section of the desulfurization tower 1. The low-temperature desulfurized slurry is sprayed out through the spray heads of the spraying device 5 to contact the high-temperature flue gas, increasing the heating area of the low-temperature desulfurized slurry, accelerating the heating of the low-temperature desulfurized slurry, and enabling the low-temperature desulfurized slurry to be quickly heated to a high-temperature slurry for repeated use.
[0030] Please refer to Figure 4 , a flue gas waste heat utilization heat exchanger 8 is connected to the input end of the flash tank 2. The flue gas waste heat utilization heat exchanger 8 is arranged in the flue. The high-temperature water output end of the flue gas waste heat utilization heat exchanger 8 is communicated with the input end of the flash tank 2, and the low-temperature water output end of the flash tank 2 is communicated with the low-temperature water input end of the flue gas waste heat utilization heat exchanger 8.
[0031] The high-temperature flue gas output from the flue in front of the desulfurization tower enters the flue gas waste heat utilization heat exchanger 8. After the high-temperature flue gas is heat-exchanged by the flue gas waste heat utilization heat exchanger 8, high-temperature water is output. The high-temperature water enters the flash tank 2 to generate flash steam. The flash steam enters the steam compressor 3 for external steam supply. The low-temperature water output end of the flash tank 2 and the low-temperature water input end of the flue gas waste heat utilization heat exchanger 8 are connected through a circulation pump 10. The saturated low-temperature water after heat exchange returns to the flue gas waste heat utilization heat exchanger 8 again under the action of the circulation pump 10 for repeated circulation, which can further fully recycle the waste heat.
[0032] Please refer to Figure 4, a economizer 7 is provided at the input end of the flue gas waste heat utilization heat exchanger 8, and an air preheater 9 is provided between the economizer (7) and the flue gas waste heat utilization heat exchanger 8.
[0033] The high-temperature flue gas is successively subjected to waste heat recovery and utilization through the economizer 7, the air preheater 9 and the flue gas waste heat utilization heat exchanger 8, and the waste heat of the output high-temperature flue gas is fully utilized to heat the desalted water so that the desalted water reaches a certain temperature; during the heat exchange process, the high-temperature flue gas transfers heat to the desalted water, causing the temperature of the desalted water to rise to become high-temperature water and enter the flash tank 2. The saturated low-temperature water output by the flash tank 2 returns to the flue gas waste heat utilization heat exchanger 8 again under the action of the circulation pump, and circulates reciprocally.
[0034] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A steam compression waste heat utilization system, characterized in that: It includes a desulfurization tower (1), the lower part of the desulfurization tower (1) is communicated with the input end of a flash tank (2) through a pipeline, the steam output end of the flash tank (2) is connected with a steam compressor (3), the steam compressor (3) is communicated with a heat user (4) through a pipeline, and the water outlet end of the flash tank (2) is communicated with the upper part of the desulfurization tower (1).
2. The steam compression waste heat utilization system according to claim 1, wherein The steam compressor (3) is driven by an electric motor or a steam turbine.
3. The steam compression waste heat utilization system according to claim 1, characterized in that, Multiple steam compressors (3) are used in cooperation to supply steam to heat users with different steam consumption parameters.
4. A steam compression waste heat utilization system according to claim 1, characterized in that, A spraying device (5) is arranged at the upper part of the desulfurization tower (1), the water outlet end of the flash tank (2) is communicated with the spraying device (5), and a slurry pump (6) is connected between the water outlet end of the flash tank (2) and the spraying device (5).
5. A steam compression waste heat utilization system according to claim 4, characterized in that, The nozzles of the spraying device (5) cover the cross section of the desulfurization tower (1).
6. The steam compression waste heat utilization system according to claim 1, characterized in that, The input end of the flash tank (2) is connected with a flue gas waste heat utilization heat exchanger (8), the flue gas waste heat utilization heat exchanger (8) is arranged in a flue, the high-temperature water output end of the flue gas waste heat utilization heat exchanger (8) is communicated with the input end of the flash tank (2), and the low-temperature water output end of the flash tank (2) is communicated with the low-temperature water input end of the flue gas waste heat utilization heat exchanger (8).
7. A steam compression waste heat utilization system according to claim 6, wherein, The flue gas waste heat utilization heat exchanger (8) is a gas-water heat exchanger.
8. A steam compression waste heat utilization system according to claim 6, characterized in that, The low-temperature water output end of the flash tank (2) is communicated with the low-temperature water input end of the flue gas waste heat utilization heat exchanger (8) through a circulation pump (10).
9. The steam compression waste heat utilization system according to claim 6, characterized in that, A economizer (7) is arranged at the input end of the flue gas waste heat utilization heat exchanger (8), and an air preheater (9) is arranged between the economizer (7) and the flue gas waste heat utilization heat exchanger (8).