An oxygen-removing feedwater system for dry quenching coke waste heat power generation and a regulating method thereof

Abstract

The present application belongs to the technical field of dry quenching waste heat power generation, and particularly relates to a dry quenching waste heat power generation oxygen removal feedwater system and a regulating method thereof, comprising an EDI electric desalination device, an extraction condensing steam turbine or a pure condensing steam turbine, a condenser, a condensate pump, a dry quenching boiler feedwater pump station desalination water tank, an oxygen removal feedwater pump, an oxygen removal feedwater regulating valve group, a three-way valve, a water-water heat exchanger, a feedwater preheater and a thermal deaerator. The present application has the beneficial effects that the desalination water tank and the secondary desalination water pump of the desalination water station are saved; the fixed pressure difference of the regulating valve is used as the main regulation, and the three-way valve is used as the secondary regulation, so that the normal operation of the sampling device is ensured; after the blowdown water is heated by the water-water heat exchanger to oxygen removal feedwater, part of the oxygen removal feedwater is sent into the dry quenching body circulating water tank for normal production, and the other part of the oxygen removal feedwater is sent back to the blowdown well to reduce the blowdown water temperature, so that the heat and water resources are fully utilized, and the adverse effects of the "white smoke" generated by blowdown on the drainage system and the environment are eliminated.

Description

Technical Field

[0001] This invention belongs to the field of dry quenching coke waste heat power generation technology, and particularly relates to a deoxygenation water supply system for dry quenching coke waste heat power generation and its regulation method. Background Technology

[0002] The deoxygenated feedwater system is a crucial component of the dry quenching waste heat power generation system. Currently, the basic process of the dry quenching deoxygenated feedwater system is as follows: Secondary demineralized water produced by the EDI electrostatic precipitator in the demineralized water station first enters the demineralized water tank, and then is pressurized by a secondary demineralized water pump and sent to the demineralized water tank of the dry quenching boiler feedwater pump station. Simultaneously, the condensate from the dry quenching power generation is also sent to the demineralized water tank of the dry quenching boiler feedwater pump station via a condensate pump. The effluent from the demineralized water tank of the dry quenching boiler feedwater pump station is pressurized by a deoxygenated feedwater pump, passes through a feedwater preheater, and is then sent to the thermal deaerator. Secondary steam from the continuous blowdown expander is connected to the thermal deaerator, and the remaining heat sources required by the thermal deaerator all require external low-pressure steam supply.

[0003] With industrial land becoming increasingly scarce, project cost control is becoming more refined. As can be seen from the above process, the deaeration feedwater system includes both the demineralized water tank of the demineralized water station and the demineralized water tank of the dry quenching boiler feedwater pump station, which increases both industrial land use and project costs.

[0004] The existing cooling method for dry quenching coke boiler sampling equipment involves extending a branch pipe from the deaerator feedwater main pipe to connect to the cooling water supply pipe of the high-temperature, high-pressure frame cooler within the sampling equipment. The cooling water return from the high-temperature, high-pressure frame cooler is then returned to the deaerator feedwater main pipe downstream of the branch point, with the return connection using a slanted joint to reduce resistance. A throttle valve is installed on the deaerator feedwater main pipe between the branch point and the return point. The opening of the throttle valve is adjusted according to the inlet pressure of the cooling water supply to the high-temperature, high-pressure frame cooler to control the flow rate of the cooling water supply and the pressure downstream of the throttle valve, ensuring smooth flow and pressure of the cooling water in the high-temperature, high-pressure frame cooler and unobstructed cooling water return. However, in actual operation, simply adjusting the throttle valve opening cannot accurately control the pressure downstream of the throttle valve, thus affecting the stable flow of deaerator water entering the sampling equipment, resulting in excessively high sampling water temperature and severely impacting the normal operation of the sampling equipment.

[0005] Currently, the continuous wastewater from dry quenching coke boilers is basically expanded in the continuous blowdown expander, then enters the periodic blowdown expander and the periodic wastewater collection, and then flows into the boiler drain header and into the blowdown well. However, the wastewater temperature of dry quenching coke boilers is basically around 95℃, which has a high energy quality. Directly sending it to the blowdown well for discharge will waste water resources and energy on the one hand, and on the other hand, the blowdown well will also produce "white smoke", which will have an adverse impact on the drainage system and the environment. Summary of the Invention

[0006] The purpose of this invention is to provide a deoxygenated feedwater system and its regulation method for dry quenching waste heat power generation, overcoming the shortcomings of existing technologies. Firstly, by optimizing the system, the demineralized water tank and secondary demineralized water pump at the demineralized water station are eliminated, reducing land occupation, investment, and operation and maintenance costs. Secondly, the deoxygenated feedwater bypass connected to the sampling equipment is arranged on both sides of the deoxygenated feedwater regulating valve group, and a three-way valve is used to connect the deoxygenated feedwater bypass outlet to the deoxygenated feedwater main pipe. The regulating valve is used as the main regulator to fix the pressure difference, and the three-way valve as the secondary regulator, ensuring the normal operation of the sampling equipment. Thirdly, the continuous wastewater, periodic wastewater, and boiler drain water from the dry quenching boiler are all subjected to steam-water separation. The secondary steam is collected and sent to the thermal deaerator to heat the feedwater, and the wastewater is heated to deoxygenated feedwater via a water-to-water heat exchanger. This fully utilizes the heat from the boiler wastewater and eliminates the adverse effects of the "white smoke" generated by the wastewater discharge on the drainage system and the environment.

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

[0008] One technical solution: 1. A deaeration feedwater system for dry quenching coke boiler waste heat power generation, comprising an EDI electrostatic precipitator, an extraction condensing steam turbine or a pure condensing steam turbine, a condenser, a condensate pump, a demineralized water tank for the dry quenching coke boiler feedwater pumping station, a deaeration feedwater pump, a deaeration feedwater regulating valve group, a three-way valve, a water-to-water heat exchanger, a feedwater preheater, and a thermal deaerator; the top of the demineralized water tank for the dry quenching coke boiler feedwater pumping station is provided with at least two inlets, including a secondary demineralized water inlet and a condensate inlet; the secondary demineralized water inlet is connected to the outlet of the EDI electrostatic precipitator through the demineralized water regulating valve group; the condensate inlet is connected to the outlet of the condenser through the condensate pump;

[0009] The bottom of the demineralized water tank of the dry quenching coke boiler feedwater pumping station is provided with an outlet, which is connected to the inlet of the deaerator feedwater pump through a pipeline;

[0010] The outlet of the deoxygenated feedwater pump is connected in sequence to the deoxygenated feedwater regulating valve group, the three-way valve, the water-to-water heat exchanger, and the feedwater preheater via the deoxygenated feedwater header, and finally to the deoxygenated feedwater inlet of the thermal deaerator; the three-way valve is a confluence valve, with its inlet connected to the deoxygenated feedwater regulating valve group and its outlet connected to the water-to-water heat exchanger.

[0011] Furthermore, it also includes a sampling device, wherein the high-temperature side cooling water inlet of the sampling device is connected to a branch pipe from the deaeration water supply main pipe before the deaeration water supply regulating valve group, and the high-temperature side cooling water outlet pipe is connected to the two-phase inlet of the three-way valve.

[0012] Furthermore, it also includes a continuous blowdown expander, a periodic blowdown expander, a condensate expansion tank, a blowdown well, a submersible blowdown pump, a multi-media filter, and a dry quenching body circulating water tank, wherein: the top secondary steam outlet of the continuous blowdown expander is connected to the secondary steam header through a pipeline, and the pipeline has a first check valve; the bottom condensate outlet of the continuous blowdown expander is connected to the condensate inlet of the periodic blowdown expander through a pipeline; the bottom wastewater outlet of the continuous blowdown expander is connected to the first boiler wastewater pipeline through a pipeline and sent to the bottom of the blowdown well;

[0013] The secondary steam outlet at the top of the periodic blowdown expander is connected to the secondary steam header via a pipeline, and a second check valve is provided on the pipeline; the wastewater outlet at the bottom of the periodic blowdown expander is connected to the first boiler wastewater pipeline via a pipeline, and the wastewater is sent to the bottom of the wastewater well.

[0014] The top of the condensate expansion container has multiple inlets connected to the drain pipe of the dry quenching coke boiler. The top secondary steam outlet is connected to the secondary steam header through a pipeline with a third check valve. The bottom sewage outlet of the condensate expansion container is connected to the first boiler sewage pipeline through a pipeline and sent to the bottom of the sewage well.

[0015] The inlet of the submersible sewage pump is located at the bottom of the sewage well; the outlet of the submersible sewage pump is connected to the inlet of the multi-media filter through a pipeline.

[0016] The hot end inlet of the water-to-water heat exchanger is connected to the outlet of the multi-media filter via a pipeline; the hot end outlet of the water-to-water heat exchanger is divided into two paths, one path is connected to the bottom of the sewage well via a first electric shut-off valve and a pipeline, and the other path is connected to the inlet of the circulating water tank of the dry quenching body via a second electric shut-off valve and a pipeline.

[0017] Furthermore, the hot end inlet of the water preheater is filled with circulating gas at 160-170°C, and the hot end outlet is filled with circulating gas at approximately 130°C.

[0018] Furthermore, the secondary steam inlet of the thermal deaerator is connected to the secondary steam header, and the outlet of the thermal deaerator is connected to the boiler feedwater pump inlet via a pipeline.

[0019] Furthermore, a retaining wall is installed at the bottom of the sewage discharge well, with the height of the retaining wall being 0.3 to 0.5 times the depth of the sewage discharge well. The first boiler sewage discharge pipeline and the pipeline after the first electric shut-off valve are arranged on one side of the retaining wall of the sewage discharge well, and the end of the pipeline is 200 to 400 mm higher than the bottom of the sewage discharge well. The suction inlet of the submersible sewage pump and the liquid level recording instrument of the sewage discharge well are arranged on the other side of the retaining wall of the sewage discharge well. The suction inlet of the submersible sewage pump is 200 to 400 mm higher than the bottom of the sewage discharge well, and the center of the overflow pipe is 300 to 1000 mm lower than the top of the sewage discharge well.

[0020] Furthermore, the filter media of the multi-media filter includes anthracite and quartz sand, and the filter cylinder and internal components are made of S30408 ​​stainless steel or 100℃ heat-resistant carbon steel lined with rubber.

[0021] Technical Solution Two: A method for regulating a deaeration feedwater system for dry quenching waste heat power generation, comprising the following steps:

[0022] 1) Demineralized water tank level regulation: The secondary demineralized water from the EDI electrostatic precipitator outlet is sent to the demineralized water tank of the dry quenching boiler feedwater pump station via the demineralized water regulating valve group. The demineralized water regulating valve group adjusts the valve opening according to the demineralized water tank level record control instrument to ensure that the level of the demineralized water tank of the dry quenching boiler feedwater pump station is maintained at the set value; The exhaust steam from the extraction condensing turbine or pure condensing turbine becomes condensate after heat exchange with the circulating cooling water in the condenser. It is then sent to the demineralized water tank of the dry quenching boiler feedwater pump station via the condensate pump to mix with the secondary demineralized water as the source of deoxygenated feedwater;

[0023] 2) Deaerator level regulation: The deaerated feedwater from the demineralized water tank outlet of the dry quenching coke boiler feedwater pumping station is pressurized by the deaerated feedwater pump and passes sequentially through the deaerated feedwater regulating valve group, three-way valve, water-to-water heat exchanger, feedwater preheater, and thermal deaerator. After thermal deaeration, qualified deaerated feedwater is sent to the boiler feedwater pump. The deaerated feedwater pump and the demineralized water tank level recording and control instrument are interlocked. When the demineralized water tank level reaches the minimum limit, the deaerated feedwater pump stops operating. The deaerated feedwater regulating valve group adjusts the valve opening according to the deaerator level recording and control instrument to ensure that the level of the thermal deaerator is maintained at the set value. The boiler feedwater pump and the deaerator level recording and control instrument are interlocked. When the level of the thermal deaerator reaches the minimum limit, the boiler feedwater pump stops operating.

[0024] 3) The sampling equipment corresponds to the pressure regulation before and after the deoxygenated feedwater main pipe. A deoxygenated feedwater bypass is led out before the deoxygenated feedwater regulating valve group. After heat exchange on the high-temperature side of the sampling equipment, it is connected to the deoxygenated feedwater main pipe after the deoxygenated feedwater regulating valve group through a three-way valve. The pressure difference is fixed by the regulating valve as the main regulation and the three-way valve as the secondary regulation to ensure that the pressure of the deoxygenated feedwater bypass pipeline after the sampling equipment is significantly higher than the pressure of the deoxygenated feedwater main pipe after the deoxygenated feedwater regulating valve group. This promotes the stable flow of deoxygenated feedwater in the sampling equipment and thus ensures the normal operation of the sampling equipment.

[0025] 4) Level regulation of the blowdown well and the circulating water tank of the dry quenching body: Continuous, periodic, and drained wastewater from the dry quenching boiler undergoes steam-water separation. Secondary steam is sent to the thermal deaerator to heat the deaerated feedwater. Boiler wastewater is connected to the blowdown well. The boiler wastewater is pressurized by a submersible blowdown pump and sent to a multi-media filter to remove some impurities. After being heated by a water-to-water heat exchanger to heat the deaerated feedwater, it is divided into two paths: one path returns to the bottom of the blowdown well via a first electric shut-off valve, and the other path is sent to the circulating water tank of the dry quenching body via a second electric shut-off valve. The long-shaft submersible sewage pump and the sewage well level recorder are interlocked. When the sewage well level reaches the minimum limit, the long-shaft submersible sewage pump stops operating. The first electric shut-off valve, the second electric shut-off valve, and the circulating water tank level recorder are interlocked. When the circulating water tank level reaches the low limit, the second electric shut-off valve opens and the first electric shut-off valve closes. When the circulating water tank level reaches the high limit, the second electric shut-off valve closes and the first electric shut-off valve opens. When the sewage well level is higher than the bottom of the overflow pipe, the sewage flows by gravity into the external drainage pipeline.

[0026] Furthermore, the pressure difference across the deaeration water supply regulating valve assembly is 0.3–0.5 MPa.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1) The demineralized water supply section of the deoxygenated feedwater system has been optimized. Specifically, the secondary demineralized water from the outlet of the EDI electrostatic precipitator enters the demineralized water tank of the dry quenching coke boiler feedwater pumping station directly after passing through the demineralized water regulating valve group. This eliminates the need for the demineralized water tank and secondary demineralized water pump of the demineralized water station, thereby reducing land occupation, investment, and operation and maintenance costs.

[0029] 2) The location of the deoxygenated feedwater bypass connection point entering the sampling equipment was rearranged and placed on both sides of the deoxygenated feedwater regulating valve group. A three-way valve was used to connect the deoxygenated feedwater bypass outlet to the deoxygenated feedwater main pipe. The regulating valve was used as the main regulator to fix the pressure difference, and the three-way valve was used as the secondary regulator. This ensured that the pressure of the deoxygenated feedwater bypass pipeline after the sampling equipment was significantly higher than the pressure of the deoxygenated feedwater main pipe after the deoxygenated feedwater regulating valve group, so as to promote the stable flow of deoxygenated feedwater in the sampling equipment and thus ensure the normal operation of the sampling equipment.

[0030] 3) The boiler blowdown and drainage water are separated into steam and water. The secondary steam is sent to the thermal deaerator to heat the deaerated feedwater. The wastewater is heated by the water-to-water heat exchanger and then part of it is sent to the dry quenching body circulating water tank for normal production. The other part is sent back to the blowdown well to reduce the temperature of the wastewater in the blowdown well. This can make full use of the heat and water resources of the boiler blowdown and drainage water, and also eliminate the adverse effects of the "white smoke" generated by the blowdown on the drainage system and the environment.

[0031] 4) Install demineralized water regulating valve group, deoxygenated feedwater regulating valve group, demineralized water tank level recording and control instrument, sewage well level recording instrument, deaerator level recording and control instrument, circulating water tank level recording instrument, first electric shut-off valve and second electric shut-off valve to ensure the normal operation of the demineralized water tank, thermal deaerator, sewage well, dry quenching body circulating water tank, deoxygenated feedwater pump, boiler feedwater pump and long shaft submersible sewage pump in the deoxygenated feedwater system. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention.

[0033] In the diagram: 1-EDI electrostatic precipitator, 2-secondary demineralized water pipeline, 3-demineralized water regulating valve group, 4-extraction condensing steam turbine or pure condensing steam turbine, 5-condenser, 6-condensate pump, 7-condensate pipeline, 8-dry quenching boiler feedwater pump station demineralized water tank, 9-demineralized water tank level recording and control instrument, 10-deoxygenated feedwater pump, 11-deoxygenated feedwater header, 12-deoxygenated feedwater regulating valve group, 13-three-way valve, 14-sampling equipment, 15-water-water heat exchanger, 16-feedwater preheater, 17-thermal deaerator, 18-dry quenching boiler feedwater pump, 19-connecting... 20-Periodic Blowout Expander, 21-Drainage Expansion Container, 22-First Boiler Blowout Pipeline, 23-Blowout Well, 24-Long-shaft Submersible Blowout Pump, 25-Second Boiler Blowout Pipeline, 26-Multi-media Filter, 27-First Electric Shut-off Valve, 28-Second Electric Shut-off Valve, 29-Blowout Well Level Recording Instrument, 30-First Check Valve, 31-Second Check Valve, 32-Third Check Valve, 33-Secondary Steam Main Pipe, 34-Deaerator Level Recording and Control Instrument, 35-Dry Quenching Coke Body Circulating Water Tank, 36-Circulating Water Tank Level Recording Instrument. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0035] To keep the drawings simple, only the parts related to the invention are shown schematically, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, components with the same structure or function are shown only schematically, or only one is labeled.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0038] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the specific embodiments used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some embodiments of the present invention. For those skilled in the art, other specific embodiments can be obtained based on these specific embodiments without creative effort.

[0040] See Figure 1 This is a schematic diagram of an embodiment of a deaeration feedwater system for dry quenching waste heat power generation according to the present invention. It includes an EDI electrostatic desalination device 1, an extraction condensing steam turbine or a pure condensing steam turbine 4, a condenser 5, a condensate pump 6, a demineralized water tank 8 of the dry quenching boiler feedwater pumping station, a deaeration feedwater pump 10, a deaeration feedwater regulating valve group 12, a three-way valve 13, a water-to-water heat exchanger 15, a feedwater preheater 16, and a thermal deaerator 17.

[0041] The top of the demineralized water tank 8 of the dry quenching coke boiler feedwater pump station is equipped with at least two inlets, including a secondary demineralized water inlet and a condensate inlet. The secondary demineralized water inlet is connected to the outlet of the EDI electrostatic precipitator 1 through the secondary demineralized water pipeline 2, the demineralized water regulating valve group 3, and the secondary demineralized water inlet. The condensate inlet is connected to the outlet of the condenser 5 through the condensate pump 6 and the condensate pipeline 7.

[0042] The demineralized water tank 8 of the dry quenching coke boiler feedwater pump station has an outlet at the bottom, which is connected to the inlet of the deaerated feedwater pump 10 through the deaerated feedwater header 11.

[0043] The outlet of the deaerator feedwater pump 10 is connected in sequence to the deaerator feedwater regulating valve group 12, the three-way valve 13, the water-to-water heat exchanger 15, and the feedwater preheater 16 via the deaerator feedwater header 11, and finally to the deaerator feedwater inlet of the thermal deaerator 17. The three-way valve 13 is a confluence valve, with its inlet one connected to the deaerator feedwater regulating valve group 12, its inlet two connected to the sampling device 14, and its outlet connected to the water-to-water heat exchanger 15.

[0044] The demineralized water regulating valve group 3 includes two parallel pipelines. The main pipeline includes two shut-off valves and one flow regulating valve, with the flow regulating valve located between the two shut-off valves. The bypass pipeline includes a shut-off valve. The deaerated feedwater regulating valve group 12 includes two parallel pipelines. The main pipeline includes two shut-off valves and one flow regulating valve, with the flow regulating valve located between the two shut-off valves. The bypass pipeline includes a throttle valve.

[0045] The system also includes a sampling device 14, whose high-temperature side cooling water inlet is connected to a branch pipe from the deaeration water supply main pipe 11 before the deaeration water supply regulating valve group 12.

[0046] The system also includes a continuous blowdown expander 19, a periodic blowdown expander 20, a condensate expansion tank 21, a blowdown well 23, a submersible blowdown pump 24, a multi-media filter 26, and a dry quenching body circulating water tank 35. The top secondary steam outlet of the continuous blowdown expander 19 is connected to the secondary steam header 33 via a pipeline, which has a first check valve 30. The bottom condensate outlet of the continuous blowdown expander 19 is connected to the condensate inlet of the periodic blowdown expander 20 via a pipeline. The bottom wastewater outlet of the continuous blowdown expander 19 is connected to the first boiler wastewater pipeline 22 via a pipeline, and the wastewater is discharged into the bottom of the blowdown well 23.

[0047] The secondary steam outlet at the top of the periodic blowdown expander 20 is connected to the secondary steam header 33 via a pipeline, and a second check valve 31 is provided on the pipeline; the wastewater outlet at the bottom of the periodic blowdown expander 20 is connected to the first boiler wastewater pipeline 22 via a pipeline, and is sent to the bottom of the blowdown well 23.

[0048] The top of the condensate expansion container 21 has multiple inlets connected to the drain pipe of the dry quenching coke boiler. The top secondary steam outlet is connected to the secondary steam header 33 through a pipeline, and there is a third check valve 32 on the pipeline. The bottom sewage outlet of the condensate expansion container 21 is connected to the first boiler sewage pipeline 22 through a pipeline and sent to the bottom of the sewage well 23.

[0049] A retaining wall is installed at the bottom of the sewage discharge well 23, with a height of 0.3 to 0.5 times the depth of the sewage discharge well. The first boiler wastewater pipeline 22 and the pipeline after the first electric shut-off valve 27 are arranged on one side of the retaining wall of the sewage discharge well 23, with the end of the pipeline 200 to 400 mm higher than the bottom of the sewage discharge well. The suction inlet of the submersible sewage pump 24 and the sewage discharge well level recording instrument 29 are arranged on the other side of the retaining wall of the sewage discharge well 23. The suction inlet of the submersible sewage pump 24 is 200 to 400 mm higher than the bottom of the sewage discharge well 23, and the center of the overflow pipe is 300 to 1000 mm lower than the top of the sewage discharge well 23. The suction inlet of the submersible sewage pump 24 is located at the bottom of the sewage discharge well 23; the outlet of the submersible sewage pump 24 is connected to the inlet of the multi-media filter 26 through the second boiler wastewater pipeline 25.

[0050] The hot end inlet of the water-to-water heat exchanger 15 is connected to the outlet of the multi-media filter 26 via a pipeline; the hot end outlet of the water-to-water heat exchanger 15 is divided into two paths: one path is connected to the bottom of the sewage well 23 via a first electric shut-off valve 27 and a pipeline, and the other path is connected to the inlet of the dry quenching coke body circulating water tank 35 via a second electric shut-off valve 28 and a pipeline. The water-to-water heat exchanger 15 is either a tubular heat exchanger or a plate heat exchanger.

[0051] The feedwater preheater 16 has a circulating gas at 160-170°C at the hot end inlet and a circulating gas at approximately 130°C at the hot end outlet.

[0052] The secondary steam inlet of the thermal deaerator 17 is connected to the secondary steam header 33, and the outlet of the thermal deaerator 17 is connected to the inlet of the boiler feedwater pump 18 through a pipeline.

[0053] The filter media of the multi-media filter 26 includes anthracite and quartz sand. The cylinder and internal components of the multi-media filter 26 are made of S30408 ​​stainless steel or 100℃ heat-resistant carbon steel lined with rubber.

[0054] The adjustment method of the deaeration feedwater system for dry quenching waste heat power generation according to an embodiment of the present invention includes the following steps:

[0055] 1) Demineralized water tank level regulation: The secondary demineralized water from the outlet of EDI electrostatic precipitator 1 is sent to the demineralized water tank 8 of the dry quenching coke boiler feedwater pump station via the demineralized water regulating valve group 3. The demineralized water regulating valve group 3 adjusts the valve opening according to the demineralized water tank level record control instrument 9 to ensure that the level of the demineralized water tank 8 of the dry quenching coke boiler feedwater pump station is maintained at the set value. The exhaust steam from the extraction condensing steam turbine or pure condensing steam turbine 4 becomes condensate after heat exchange with the circulating cooling water in the condenser 5. It is then sent to the demineralized water tank 8 of the dry quenching coke boiler feedwater pump station via the condensate pump 6 to mix with the secondary demineralized water as the source of deoxygenated feedwater.

[0056] 2) Deaerator level regulation: The deaerated feedwater from the outlet of the demineralized water tank 8 of the dry quenching coke boiler feedwater pump station is pressurized by the deaerated feedwater pump 10 and passes sequentially through the deaerated feedwater regulating valve group 12, three-way valve 13, water-to-water heat exchanger 15, feedwater preheater 16, and thermal deaerator 17. After obtaining qualified deaerated feedwater through thermal deaeration, it is sent to the boiler feedwater pump 18. Among them, the deaerated feedwater pump 10 and the demineralized water tank level recording and control instrument 9 are interlocked. When the demineralized water tank level reaches the minimum limit value, the deaerated feedwater pump 10 stops running. The deaerated feedwater regulating valve group 12 adjusts the valve opening according to the deaerator level recording and control instrument 34 to ensure that the level of the thermal deaerator 17 is maintained at the set value. The boiler feedwater pump 18 and the deaerator level recording and control instrument 34 are interlocked. When the level of the thermal deaerator 17 reaches the minimum limit value, the boiler feedwater pump 18 stops running.

[0057] 3) The sampling equipment corresponds to the pressure regulation before and after the deoxygenated feedwater main pipe. A deoxygenated feedwater bypass is led out before the deoxygenated feedwater regulating valve group 12, passes through the high-temperature side heat exchange of the sampling equipment 14, and is connected to the deoxygenated feedwater main pipe 11 after the deoxygenated feedwater regulating valve group 12 via a three-way valve 13. The pressure difference is fixed by the regulating valve as the main regulation. The pressure difference before and after the deoxygenated feedwater regulating valve group is 0.3 to 0.5 MPa. The three-way valve 13 is used as the secondary regulation to ensure that the pressure of the deoxygenated feedwater bypass pipeline after the sampling equipment 14 is significantly higher than the pressure of the deoxygenated feedwater main pipe 11 after the deoxygenated feedwater regulating valve group 12, so as to promote the stable flow of deoxygenated feedwater in the sampling equipment 14, thereby ensuring the normal operation of the sampling equipment 14.

[0058] 4) Level regulation of the sewage discharge well and the circulating water tank of the dry quenching body: The continuous sewage discharge, periodic sewage discharge, and drain water of the dry quenching boiler are separated by steam-water separation. Secondary steam is sent to the thermal deaerator 17 to heat the deaerated feedwater. The boiler sewage discharge is connected to the sewage discharge well 23. The boiler sewage discharge is pressurized by the submersible sewage pump 24 and sent to the multi-media filter 26 to filter out some impurities. After being heated by the water-to-water heat exchanger 15 to heat the deaerated feedwater, it is divided into two paths. One path returns to the bottom of the sewage discharge well 23 through the first electric shut-off valve 27, and the other path is sent to the circulating water tank 35 of the dry quenching body through the second electric shut-off valve 28. Among them, the long The long-shaft submersible sewage pump 24 and the sewage well level recording instrument 29 are interlocked. When the sewage well level reaches the minimum limit value, the long-shaft submersible sewage pump 24 stops operating. The first electric shut-off valve 27, the second electric shut-off valve 28 and the circulating water tank level recording instrument 36 are interlocked. When the circulating water tank level reaches the low limit value, the second electric shut-off valve 28 opens and the first electric shut-off valve 27 closes. When the circulating water tank level reaches the high limit value, the second electric shut-off valve 28 closes and the first electric shut-off valve 27 opens. When the sewage well level is higher than the bottom of the overflow pipe, the sewage flows by gravity into the external drainage pipeline.

[0059] In this embodiment of the invention, the demineralized water supply section of the deoxygenated feedwater system, namely the secondary demineralized water from the outlet of the EDI electrostatic precipitator 1, directly enters the demineralized water tank 8 of the dry quenching coke boiler feedwater pump station after passing through the demineralized water regulating valve group, thus eliminating the need for the demineralized water tank and the secondary demineralized water pump of the demineralized water station and reducing costs.

[0060] The deoxygenated feedwater bypass connection point of the sampling device 14 is arranged on both sides of the deoxygenated feedwater regulating valve group 12. The regulating valve is used as the main regulator to fix the pressure difference, and the three-way valve 13 is used as the secondary regulator. This ensures that the pressure of the deoxygenated feedwater bypass pipeline after the sampling device 14 is significantly higher than the pressure of the deoxygenated feedwater main pipeline after the deoxygenated feedwater regulating valve group 12, so as to promote the stable flow of deoxygenated feedwater in the sampling device and thus ensure the normal operation of the sampling device.

[0061] The boiler blowdown and drainage water are separated into steam and water. Secondary steam is sent to the thermal deaerator 17 to heat the deaerated feedwater. After the blowdown water is heated by the water-to-water heat exchanger 15, part of it is sent to the dry quenching body circulating water tank 35 for normal production, and the other part is sent back to the blowdown well 23 to reduce the temperature of the blowdown water in the blowdown well. This can make full use of the heat and water resources of the boiler blowdown and drainage water, and also eliminate the adverse effects of the "white smoke" generated by the blowdown on the drainage system and the environment.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coke dry quenching cogeneration deaerating feed water system, characterized by, The EDI electric desalination device, the extraction condensing steam turbine or pure condensing steam turbine, the condenser, the condensate pump, the dry quenching coke boiler feed water pump station desalination tank, the deaerating feed water pump, the deaerating feed water regulating valve group, the three-way valve, the water-water heat exchanger, the feed water preheater and the thermal deaerator are included. The top of the dry quenching coke boiler feed water pump station desalination tank is provided with at least two inlets, including a secondary desalination water inlet and a condensate water inlet. The bottom of the dry quenching coke boiler feed water pump station desalination tank is provided with an outlet connected with the inlet of the deaerating feed water pump through a pipeline. The outlet of the deaerating feed water pump is connected with the deaerating feed water regulating valve group, the three-way valve, the water-water heat exchanger, the feed water preheater and the thermal deaerator in sequence through a pipeline. The sampling device is connected with a branch pipeline of the deaerating feed water mother pipeline before the deaerating feed water regulating valve group.

2. The oxygenated feedwater system for a coke dry quenching waste heat power generation according to claim 1, characterized by The continuous blowdown expander, the periodic blowdown expander, the drain expander, the blowdown well, the submersible blowdown pump, the multi-medium filter and the dry quenching body circulating water tank are further included. The top secondary steam outlet of the continuous blowdown expander is connected with the secondary steam mother pipeline through a pipeline, and a first check valve is arranged on the pipeline. The bottom blowdown water outlet of the continuous blowdown expander is connected with the first boiler blowdown water pipeline through a pipeline and sent to the bottom of the blowdown well. The top secondary steam outlet of the periodic blowdown expander is connected with the secondary steam mother pipeline through a pipeline, and a second check valve is arranged on the pipeline. The bottom blowdown water outlet of the periodic blowdown expander is connected with the first boiler blowdown water pipeline through a pipeline and sent to the bottom of the blowdown well. The top secondary steam outlet of the drain expander is connected with the secondary steam mother pipeline through a pipeline, and a third check valve is arranged on the pipeline.

3. The oxygenated feedwater system for a coke dry quenching waste heat power generation according to claim 1, characterized by The submersible blowdown pump suction inlet is arranged at the bottom of the blowdown well.

4. The oxygenated feedwater system for a coke dry quenching waste heat power generation system according to claim 2, characterized by The water-water heat exchanger hot end inlet is connected with the multi-medium filter outlet through a pipeline. The feed water preheater hot end inlet is 160-170 DEG C circulating gas, and the hot end outlet is 130 DEG C circulating gas. The secondary steam inlet of the thermal deaerator is connected with the secondary steam mother pipeline, and the outlet of the thermal deaerator is connected with the inlet of the boiler feed water pump through a pipeline.

5. The oxygenated feedwater system for a coke dry quenching waste heat power generation system according to claim 2, characterized by The bottom of the blowdown well is provided with a retaining wall, the height of the retaining wall is 0.3-0.5 times the depth of the blowdown well, the first boiler blowdown water pipeline and the first electric cut-off valve rear pipeline are arranged on one side of the blowdown well retaining wall, and the pipeline ends are 200-400 mm higher than the bottom of the blowdown well, the suction inlet of the submersible blowdown pump and the blowdown well liquid level recording instrument are arranged on the other side of the blowdown well retaining wall, the suction inlet of the submersible blowdown pump is 200-400 mm higher than the bottom of the blowdown well, and the center of the overflow pipe is 300-1000 mm lower than the top of the blowdown well.

6. The oxygenated feedwater system for a coke dry quenching waste heat power generation system according to claim 2, characterized by The filter material of the multi-medium filter comprises anthracite and quartz sand, and the material of the cylinder and internal components of the multi-medium filter is S30408 stainless steel or 100 DEG C temperature-resistant carbon steel lined with rubber.

7. The method of claim 1 to 6, wherein the method is characterized in that, The method comprises the following steps: 1) Salt water tank liquid level adjustment, the secondary desalted water from the outlet of the EDI electric desalting equipment is sent into the desalted water tank of the dry quenching coke oven feed water pump station through the desalted water adjusting valve group, the desalted water adjusting valve group adjusts the valve opening degree according to the desalted water tank liquid level recording control instrument, and the liquid level of the desalted water tank of the dry quenching coke oven feed water pump station is maintained at a set value; the exhaust steam of the extraction condensing steam turbine or the pure condensing steam turbine is changed into condensate water after heat exchange with the circulating cooling water in the condenser, and the condensate water is sent into the desalted water tank of the dry quenching coke oven feed water pump station to mix with the secondary desalted water, so as to serve as the source of the deoxidized feed water; 2) Deaerator liquid level adjustment, the deoxidized feed water from the outlet of the desalted water tank of the dry quenching coke oven feed water pump station is pressurized by the deoxidized feed water pump, sequentially passes through the deoxidized feed water adjusting valve group, the three-way valve, the water-water heat exchanger, the feed water preheater and the thermal deaerator, is sent to the boiler feed water pump after qualified deoxidized feed water is obtained through the thermal deaeration, the deoxidized feed water pump and the desalted water tank liquid level recording control instrument are interlocked, when the liquid level of the desalted water tank reaches the minimum limit value, the deoxidized feed water pump stops running, the deoxidized feed water adjusting valve group adjusts the valve opening degree according to the deaerator liquid level recording control instrument, and the liquid level of the thermal deaerator is maintained at a set value, the boiler feed water pump and the deaerator liquid level recording control instrument are interlocked, and when the liquid level of the thermal deaerator reaches the minimum limit value, the boiler feed water pump stops running; 3) Sampling equipment corresponding deoxidized feed water mother pipe front and rear pressure adjustment, the deoxidized feed water bypass is led out before the deoxidized feed water adjusting valve group, passes through the high-temperature side heat exchange of the sampling equipment, is connected to the deoxidized feed water mother pipe after the deoxidized feed water adjusting valve group through the three-way valve, the fixed pressure difference of the adjusting valve is used as the main adjustment, the three-way valve is used as the auxiliary adjustment, the pressure of the deoxidized feed water bypass pipeline after the sampling equipment is significantly higher than that of the deoxidized feed water mother pipe after the deoxidized feed water adjusting valve group, the deoxidized feed water is stably flowed in the sampling equipment, and then the normal operation of the sampling equipment is ensured. 4) The blowdown well and the dry quenching body circulating water tank liquid level regulation, the dry quenching boiler continuous blowdown water, periodic blowdown water and blowdown water through steam-water separation, the secondary steam is sent into the heat deaerator to heat and deaerate the feedwater, and the boiler blowdown water is connected to the blowdown well; the boiler blowdown water is pressurized through the subsea blowdown pump, is sent into the multi-medium filter to filter out part of impurities, and then is divided into two ways after heating the feedwater through the water-water heat exchanger, one way is returned to the bottom of the blowdown well through the first electric cut-off valve, and the other way is sent to the dry quenching body circulating water tank through the second electric cut-off valve; wherein, the long shaft subsea blowdown pump and the blowdown well liquid level recorder instrument interlock, when the blowdown well liquid level reaches the minimum limit value, the long shaft subsea blowdown pump stops running; the first electric cut-off valve, the second electric cut-off valve and the circulating water tank liquid level recorder instrument interlock, when the circulating water tank liquid level reaches the low limit value, the second electric cut-off valve is opened, and the first electric cut-off valve is closed; when the circulating water tank liquid level reaches the high limit value, the second electric cut-off valve is closed, and the first electric cut-off valve is opened; when the blowdown well liquid level is higher than the bottom of the overflow pipe, the blowdown water is self-flowed into the external drain pipeline.

8. The method of claim 7, wherein the method further comprises: The front and back pressure difference of the deaerated feedwater regulating valve group is 0.3-0.5 MPa.

Images