Vacuum optimization energy-saving production device and method for dragging steam turbine in coal chemical industry

Abstract

The invention discloses a coal chemical industry dragging steam turbine vacuum optimization energy-saving production device and method, and belongs to the technical field of coal chemical industry, the production device comprises a steam exhaust condensation mechanism, a steam injection and extraction mechanism and an oil ring vacuum mechanism, and the steam exhaust condensation mechanism is connected with the steam injection and extraction mechanism through a pipeline; the steam injection and extraction mechanism is connected with the oil ring vacuum mechanism through a pipeline, the oil ring vacuum mechanism is connected with the steam exhaust and condensation mechanism through a pipeline, and the production method comprises the steps that vacuum is rapidly established and steam is recycled before starting, the first-stage steam extractor and the second-stage steam extractor suck non-condensable gas and condense the non-condensable gas, and the oil ring vacuum mechanism operates independently under the high-temperature working condition in summer. According to the vacuum optimization energy-saving production device and method for the coal chemical dragging steam turbine, the requirements of two operation working conditions before starting of the steam turbine and during normal production are met, waste of steam is reduced, meanwhile, the problems of low condensation efficiency and poor vacuum operation in summer are solved, and the purposes of stable production, energy conservation and consumption reduction are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of coal chemical industry, and in particular to a vacuum optimization and energy-saving production device and method for a coal chemical industry driven steam turbine. Background Art

[0002] In the coal chemical ammonia synthesis process, the process gas needs to be pressurized by a compressor before being fed into the ammonia synthesis process. The compressor accounts for a large proportion of system consumption. Each compressor unit is usually driven by a fully condensing steam turbine. The turbine condenser vacuum system adopts a steam jet extraction system, which consists of a starting steam extraction unit, a first-stage steam extraction unit, a second-stage steam extraction unit, and an extraction cooler. The vacuum before the turbine is started is usually established by the starting steam extraction unit. During this process, the steam extraction unit consumes a large amount of steam, and the steam and extracted non-condensable steam are directly discharged into the air, causing waste and increasing production costs. After normal production, in order to maintain the vacuum of the steam turbine, the steam extraction unit is stopped and started, and the first-stage and second-stage steam extraction units are opened. The steam is cooled in the extraction condenser and then recovered. For the steam jet extraction system, the nozzle is more likely to be clogged. At the same time, the temperature and pressure of the steam after entering the expansion chamber are high, and the flange joint surface of the equipment body is prone to leakage. Maintenance will also cause risks such as unit shutdown. In addition, affected by the temperature, the injection water temperature in summer is generally above 32°C, which causes the condenser and steam extraction system to be unable to reach the optimal working conditions. The condenser vacuum is difficult to maintain a good level, which can easily lead to vacuum system failure and shutdown, resulting in huge losses. Summary of the Invention

[0003] The purpose of the present invention is to provide a vacuum optimization and energy-saving production device and method for a coal chemical driven steam turbine. By adding a direct-extraction vacuum mechanism, namely an oil ring vacuum mechanism, to replace the existing starting steam jet extraction mechanism, it meets the two operating conditions before the turbine is started and during normal production. It operates in parallel with the original first-stage steam extractor and second-stage steam extractor, or operates alone, thereby reducing the large amount of steam consumption and waste caused by the start-up of the steam jet extraction mechanism. At the same time, it solves the problem of low condensation efficiency and poor vacuum operation caused by high temperature in summer, thereby achieving the purpose of stable production and energy saving and consumption reduction.

[0004] To achieve the above-mentioned objectives, the present invention provides a coal chemical driven steam turbine vacuum optimization and energy-saving production device, including an exhaust steam condensing mechanism, a steam jet extraction mechanism and an oil ring vacuum mechanism. The exhaust steam condensing mechanism is connected to the steam jet extraction mechanism through a pipeline, the steam jet extraction mechanism is connected to the oil ring vacuum mechanism through a pipeline, and the oil ring vacuum mechanism is connected to the exhaust steam condensing mechanism through a pipeline.

[0005] Preferably, the exhaust steam condensation mechanism includes a condenser, a hydrophobic expansion tank, a heat trap level gauge and a condensate pump. The hydrophobic expansion tank is communicated with the condenser, and the condenser and the condensate pump are connected through a condensate pump inlet pipe. A heat trap level gauge is provided on one side of the heat trap at the bottom of the condenser. The condenser is provided with a turbine exhaust steam inlet pipe, a circulating water supply pipe and a circulating water return pipe, and a condensate pump inlet valve is provided on the condensate pump inlet pipe.

[0006] Preferably, the steam extraction mechanism includes a first-stage steam extraction unit, a second-stage steam extraction unit, a first-stage steam extraction cooler, a second-stage steam extraction cooler, a first-stage steam extraction unit air valve, a second-stage steam extraction unit air pipeline valve and a condensate outlet valve. A common pipe pass is provided between the first-stage steam extraction cooler and the second-stage steam extraction cooler. The condensate pump is connected to the common pipe pass through the steam extraction cooler inlet pipe. The common pipe pass is provided with a condensate outlet pipe. The shell side of the first-stage steam extraction cooler is connected to the hydrophobic expansion tank through the first-stage steam extraction unit condensate discharge pipe. The shell side of the second-stage steam extraction cooler is connected to the hydrophobic expansion tank through the second-stage steam extraction unit condensate discharge pipe. The shell side of the first-stage steam extraction cooler is connected to the first-stage steam extraction unit through a pipe. One end of the first-stage steam extraction unit is connected to the power steam pipeline, and the other end thereof is connected to the non-condensing steam pipeline. The shell side of the second-stage steam extraction cooler is connected to the second-stage steam extraction unit through a pipe. One end of the second-stage steam extraction unit is connected to the power steam pipeline, and the other end thereof is connected to the shell side of the first-stage steam extraction cooler through a pipe. The shell side of the second-stage steam extraction cooler is provided with a first vent pipe.

[0007] Preferably, a condensate pump outlet valve is provided on the inlet pipe of the extraction cooler, a condensate discharge valve and a first steam trap are provided on the condensate discharge pipe of the secondary extraction cooler near the secondary extraction cooler, a first extraction valve is provided on the power steam pipe near the primary extraction cooler, a second extraction valve is provided near the secondary extraction cooler, a primary extraction air valve is provided on the non-condensing steam pipe near the primary extraction cooler, a secondary extraction air pipe valve is provided on the pipe connecting the secondary extraction cooler and the shell side of the primary extraction cooler, and a condensate delivery valve is provided on the condensate delivery pipe.

[0008] Preferably, the oil ring vacuum mechanism includes a vacuum pressure gauge, a precooler air inlet valve, a precooler, a second steam trap, an oil ring vacuum pump, a separator, an afterheat exchanger and a temperature gauge, the condenser is connected to the precooler through a non-condensing steam pipe, the steam expansion tank is connected to the precooler through a precooler condensate pipe, the precooler is connected to the oil ring vacuum pump through a pipe, the oil ring vacuum pump is connected to the separator through a pipe, the separator is provided with a second vent pipe, the separator is connected to the afterheat exchanger through a pipe, the afterheat exchanger is connected to the oil ring vacuum pump through a vacuum lubricating oil pipe, and the precooler and the afterheat exchanger are both provided with circulating water supply and circulating water return.

[0009] Preferably, a vacuum pressure gauge and a precooler air inlet valve are provided on the non-condensing steam pipeline, a second steam trap is provided on the precooler condensate pipeline, and a temperature gauge is provided on the vacuum lubricating oil pipeline.

[0010] Preferably, the condensate delivery valve is connected to the hot trap level gauge via a cable.

[0011] The present invention also provides a coal chemical industry driven steam turbine vacuum optimization energy-saving production method, which uses the above-mentioned coal chemical industry driven steam turbine vacuum optimization energy-saving production device, including the following steps:

[0012] S1: The exhaust steam and non-condensable steam from the steam turbine enter the shell side of the condenser, where they exchange heat with the circulating water wall in the tube side. The steam condenses and enters the heat sink at the bottom of the condenser. It then enters the condensate pump through the condensate pump inlet pipe. After the steam condensate is pressurized, it enters the common tube side through the extraction cooler inlet pipe. It then exchanges heat with the steam injected from the first and second extraction units in the shell side. The working steam from the first and second extraction units and the non-condensable steam extracted from the condenser condense into steam condensate. After the condensate temperature in the tube side is increased, it is sent to the boiler section through the condensate outlet valve for the next cycle.

[0013] S2. The working steam enters the first-stage extraction unit through the power steam pipe. As the cross-sectional area of ​​the first-stage extraction unit nozzle gradually decreases, the steam flow rate increases sharply and the pressure drops. When the pressure at the nozzle outlet is lower than the pressure inside the condenser, the non-condensable steam and a small amount of steam mixture in the condenser are sucked into the mixing chamber in front of the nozzle through the non-condensable steam pipe. The sucked mixture is further mixed with the high-speed flowing working steam in the mixing chamber and discharged at a high pressure. It then enters the shell side of the first-stage extraction cooler. The mixed gas is cooled by the low-temperature condensate in the tube side. After condensation, the steam passes through the first-stage extraction unit condensate discharge pipe and enters the hydrophobic expansion chamber under the influence of the potential difference. The non-condensable steam in the shell side of the first-stage extraction cooler is then sucked into the mixing chamber in front of the nozzle of the second-stage extraction cooler through the valve of the air duct of the second-stage extraction cooler. The principle is the same as that of the first-stage extraction cooler. The sucked-in mixture is further mixed with the high-speed working steam in the mixing chamber of the second-stage extraction cooler and pressurized before being discharged. It then enters the shell side of the second-stage extraction cooler and continues to exchange heat with the condensate after heat exchange from the tube side of the first-stage extraction cooler. The mixture of the non-condensable steam in the shell side and a small amount of steam is cooled. After condensation, the steam passes through the first steam trap and the condensate discharge pipe of the second-stage extraction cooler into the steam trap expansion tank. The non-condensable steam is discharged into the atmosphere through the first vent pipe.

[0014] S3. The non-condensable steam and steam mixture passes through the non-condensable steam pipeline and the air inlet valve of the precooler, and enters the shell side of the precooler, and exchanges heat with the circulating cooling water in the tube side. The steam in the mixture is condensed, and the steam condensate enters the hydrophobic expansion tank through the condensate pipeline of the precooler by utilizing the potential difference. The non-condensable steam is sucked into the oil ring vacuum pump through the pipeline, and after being mixed with the lubricating oil in the oil ring vacuum pump, it enters the separator through the pipeline. The non-condensable steam is discharged into the atmosphere through the second vent pipeline. The separated vacuum lubricating oil enters the shell side of the post-heat exchanger through the pipeline, and exchanges heat with the circulating cooling water in the tube side through the partition wall. After reducing the temperature, it enters the inlet of the oil ring vacuum pump through the vacuum lubricating oil pipeline for the next cycle.

[0015] Preferably, in S1, the vacuum index of the steam turbine condenser is controlled between -88 kPa and -94 kPa.

[0016] Preferably, in S3, the temperature of the lubricating oil entering the oil ring vacuum pump is controlled between 35-38°C.

[0017] Therefore, the present invention adopts the above-mentioned coal chemical driven steam turbine vacuum optimization energy-saving production device and method, and replaces the existing starting steam jet extraction mechanism by adding a direct extraction vacuum mechanism, namely an oil ring vacuum mechanism, to meet the two operating conditions before the turbine is started and during normal production. It operates in parallel with the original first-stage steam extractor and second-stage steam extractor, or operates alone, reducing the large amount of steam consumption and waste caused by the start-up of the steam jet extraction mechanism, and at the same time solving the problem of low condensation efficiency and poor vacuum operation caused by high temperature in summer, so as to achieve the purpose of stable production and energy saving and consumption reduction.

[0018] The present invention provides a vacuum optimization and energy-saving production device and method for a coal chemical industry driven steam turbine, which has the following beneficial effects:

[0019] The coal chemical industry driven steam turbine vacuum optimization and energy-saving production device provided by the present invention adds a direct-extraction vacuum mechanism, namely, an oil ring vacuum mechanism. Before the steam turbine is started, the oil ring vacuum mechanism is turned on, and the non-condensable steam and a small amount of steam in the steam turbine condenser are drawn into the precooler by the oil ring vacuum mechanism, and the steam is condensed and recovered. The non-condensable steam is then sent to the separator via the oil ring vacuum pump, and the non-condensable steam is discharged to achieve the vacuum degree requirement of -88kPa before the steam turbine is started. At the same time, the vacuumed steam (1.5t / h) is fully recovered, thereby reducing losses and lowering costs.

[0020] Summer temperatures reduce the cooling efficiency of the condenser's circulating water and increase the condensate temperature, leading to high extraction cooler temperatures. This impacts the efficiency of the first and second extraction units, worsening the vacuum. For every 1 kPa increase in vacuum, turbine power consumption and steam consumption increase by 0.5%. The oil ring vacuum mechanism is insensitive to temperature. By activating it independently during summer production, the turbine vacuum index can be stabilized at or below -88 kPa, ensuring stable turbine operation and reducing steam consumption by 4.5 t / h.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a process flow diagram of an embodiment of a vacuum optimization and energy-saving production device and method for a coal chemical driven steam turbine according to the present invention.

[0023] Reference numerals

[0024] 1. Condenser; 2. Non-condensing steam pipeline; 3. First-stage steam extraction unit; 4. Second-stage steam extraction unit; 5. First-stage steam extraction cooler; 6. Second vent pipeline; 7. Second steam trap; 8. Condensate pump; 9. First-stage steam extraction unit air valve; 10. Second-stage steam extraction unit air pipeline valve; 11. First-stage steam extraction unit condensate discharge pipeline; 12. Second-stage steam extraction unit condensate discharge pipeline; 13. Steam extraction cooler inlet pipeline; 14. Condensate outlet valve; 15. Precooler air inlet valve; 16. Precooler; 17. Oil ring vacuum pump; 18. Backstage Heat exchanger; 19. Separator; 20. Vacuum pressure gauge; 21. Power steam pipeline; 22. Condensate pump inlet pipeline; 23. Secondary extraction cooler; 24. Steam expansion tank; 25. Precooler condensate pipeline; 26. Vacuum lubricating oil pipeline; 27. Thermometer; 28. Heat trap level gauge; 29. ​​Condensate pump inlet valve; 30. Condensate pump outlet valve; 31. Condensate discharge valve; 32. First steam trap; 33. First extraction valve; 34. Second extraction valve; 35. First vent pipeline; 36. Common pipe line. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0026] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0027] Example

[0028] like Figure 1As shown, the present invention provides a vacuum optimization and energy-saving production device for a coal chemical driven steam turbine, comprising an exhaust condensing mechanism, a steam jet extraction mechanism, and an oil ring vacuum mechanism. The exhaust condensing mechanism is connected to the steam jet extraction mechanism via a pipeline, the steam jet extraction mechanism is connected to the oil ring vacuum mechanism via a pipeline, and the oil ring vacuum mechanism is connected to the exhaust condensing mechanism via a pipeline. The exhaust condensing mechanism can condense and increase the pressure of the exhaust steam of the steam turbine. The steam jet extraction mechanism is used to condense the non-condensable steam and a small amount of steam mixture and working steam in the condenser 1 into condensate to achieve vacuum operation of the steam turbine condenser 1. The oil ring vacuum mechanism extracts the non-condensable steam in the condenser 1 to maintain the vacuum degree of the condenser 1. It can operate in parallel with the steam jet extraction mechanism or independently.

[0029] The exhaust condensation mechanism includes a condenser 1, a hydrophobic expansion tank 24, a heat-trap level gauge 28, and a condensate pump 8. The condenser 1 is equipped with a turbine exhaust inlet pipe, a circulating water supply pipe, and a circulating water return pipe. The circulating cooling water condenses the steam flowing into the turbine exhaust inlet pipe into condensate. A heat-trap level gauge 28 is installed on the heat-trap side of the lower portion of the condenser 1 to display the condensate level within the heat-trap. The hydrophobic expansion tank 24 communicates with the condenser 1. The condenser 1 is connected to the condensate pump 8 via a condensate pump inlet pipe 22, which is equipped with a condensate pump inlet valve 29. The condensate pump 8 is used to increase the pressure of the condensate.

[0030] The steam jet extraction mechanism includes a first-stage extraction unit 3, a second-stage extraction unit 4, a first-stage extraction cooler 5, a second-stage extraction cooler 23, a first-stage extraction unit air valve 9, a second-stage extraction unit air line valve 10, and a condensate outlet valve 14. A common pipe pass 36 is located between the first-stage extraction cooler 5 and the second-stage extraction cooler 23. The condensate pump 8 is connected to the common pipe pass 36 via the extraction cooler inlet pipe 13. A condensate outlet pipe is provided in the common pipe pass 36, along with a condensate pump outlet valve 30 and a condensate outlet valve 14. After being pressurized by the condensate pump 8, the condensate enters the common pipe pass 36, where it undergoes a wall-to-wall heat exchange with the steam in the shell side. After the condensate temperature is elevated within the pipe pass, it is delivered to the boiler section through the condensate outlet valve 14 for the next cycle. The condensate delivery valve 14 is connected to the heat trap level gauge 28 through a cable. By adjusting the opening of the condensate delivery valve 14, the index of the heat trap level gauge 28 is controlled between 50% and 75%, ensuring the stability of the heat trap level when the load fluctuates and ensuring the normal production of the steam injection and extraction mechanism.

[0031] The shell side of the first-stage extraction cooler 5 is connected to the hydrophobic expansion tank 24 through the first-stage extraction cooler condensate discharge pipe 11, the shell side of the second-stage extraction cooler 23 is connected to the hydrophobic expansion tank 24 through the first-stage extraction cooler condensate discharge pipe 12, the shell side of the first-stage extraction cooler 5 is connected to the first-stage extraction cooler 3 through a pipe, one end of the first-stage extraction cooler 3 is connected to the power steam pipe 21, and the other end is connected to the non-condensing steam pipe 2, the shell side of the second-stage extraction cooler 23 is connected to the second-stage extraction cooler 4 through a pipe, one end of the second-stage extraction cooler 4 is connected to the power steam pipe 21, and the other end is connected to the first-stage extraction cooler 3 through a pipe. The shell side of the steam cooler 5 is connected, the shell side of the secondary extraction steam cooler 23 is provided with a first vent pipe 35, the first extraction steam condensate discharge pipe 12 is provided with a condensate discharge valve 31 and a first steam trap 32 near the secondary extraction steam cooler 23, the power steam pipe 21 is provided with a first extraction steam valve 33 near the first extraction steam cooler 3, and a second extraction steam valve 34 is provided near the second extraction steam cooler 4, the non-condensing steam pipe 2 is provided with a first extraction steam air valve 9 near the first extraction steam cooler 3, and a second extraction steam air pipe valve 10 is provided on the pipe connecting the shell side of the second extraction steam cooler 4 and the first extraction steam cooler 5. The first-stage extraction unit 3 and the second-stage extraction unit 4 are used to extract a mixture of non-condensable steam and a small amount of steam from the condenser 1. The mixture is mixed with the working steam and then enters the shell side of the first-stage extraction cooler 5. After entering the shell side, it is cooled by the low-temperature condensate in the tube side. The condensed condensate enters the steam expansion tank 24, and the non-condensable steam then enters the second-stage extraction unit 4 and the second-stage extraction cooler 23 in sequence. The condensed condensate enters the steam expansion tank 24 through the first steam trap 32, and the non-condensable steam is discharged into the atmosphere through the first vent line 35. The first steam trap 32 separates the condensate from the non-condensable steam.

[0032] The oil ring vacuum system includes a vacuum pressure gauge 20, a precooler air inlet valve 15, a precooler 16, a second steam trap 7, an oil ring vacuum pump 17, a separator 19, a post-heat exchanger 18, and a thermometer 27. The condenser 1 is connected to the precooler 16 via a non-condensing steam pipe 2, and the steam expansion tank 24 is connected to the precooler 16 via a precooler condensate pipe 25. The non-condensing steam pipe 2 is equipped with a vacuum pressure gauge 20 and a precooler air inlet valve 15, and the precooler condensate pipe 25 is equipped with a second steam trap 7. A mixture of non-condensing steam and steam flows through the non-condensing steam pipe 2 into the shell side of the precooler 16, where it undergoes inter-wall heat exchange with the circulating cooling water in the tube side. The steam in the mixture is condensed, and the condensate enters the steam expansion tank 24 via the precooler condensate pipe 25 using the potential difference. The non-condensing steam is then drawn into the oil ring vacuum pump 17 through the pipes. The vacuum pressure gauge 20 on the non-condensing steam pipeline 2 can monitor the vacuum degree of the turbine condenser 1. By adjusting the precooler air inlet valve 15 and the first-stage steam extractor air valve 9, the vacuum degree can be kept within the economic indicators.

[0033] The oil ring vacuum pump 17 is connected to the precooler 16 via a pipeline. The separator 19 is also connected to the oil ring vacuum pump 17 via a pipeline. The separator 19 is equipped with a second vent line 6. The separator 19 is also connected to the afterheat exchanger 18 via a pipeline. The afterheat exchanger 18 is connected to the oil ring vacuum pump 17 via a vacuum lubricating oil pipeline 26. A thermometer 27 is installed on the vacuum lubricating oil pipeline 26. After mixing with the lubricating oil in the oil ring vacuum pump 17, the non-condensable vapor enters the separator 19 through a pipeline. The non-condensable vapor is discharged into the atmosphere via the second vent line 6. The separated vacuum lubricating oil enters the shell side of the afterheat exchanger 18 via a pipeline, where it exchanges heat with the circulating cooling water in the tube side. After its temperature is reduced, it enters the inlet of the oil ring vacuum pump 17 through the vacuum lubricating oil pipeline 26 for the next cycle. The thermometer 27 on the vacuum lubricating oil pipeline 26 monitors the temperature of the lubricating oil entering the oil ring vacuum pump 17.

[0034] The present invention also provides a coal chemical industry driven steam turbine vacuum optimization energy-saving production method, which uses the above-mentioned coal chemical industry driven steam turbine vacuum optimization energy-saving production device, including the following steps:

[0035] S1. At the initial stage of startup, the precooler air inlet valve 15 and the first-stage steam extraction valve 9 are opened at the same time, and the oil ring vacuum mechanism and the steam ejection mechanism are operated in parallel to ensure the rapid establishment of vacuum at the initial stage of startup. At the same time, the small amount of steam entrained in the working steam and non-condensable steam is condensed and recovered, which reduces the consumption of desalted water and improves the economic operation efficiency of the system. By adjusting the precooler air inlet valve 15 and the first-stage steam extraction valve 9, the vacuum index of the turbine condenser 1 can be controlled between -88kPa and -94kPa. In the summer, when the temperature is high, the first-stage steam extraction valve 9 is closed, and the oil ring vacuum mechanism is operated alone to stabilize the turbine vacuum. The air density index requirements are met to ensure economic stability of summer production; exhaust steam and non-condensable steam from the driving steam turbine enter the shell side of condenser 1, exchange heat with the wall of circulating water in the tube side, condense and enter the heat sink at the bottom of condenser 1, enter condensate pump 8 through condensate pump inlet pipe 22, and after the steam condensate is pressurized, enter the common tube side 36 through the extraction cooler inlet pipe 13, and exchange heat with the steam injected from the first-stage extraction unit 3 and the second-stage extraction unit 4 in the shell side. The working steam of the first-stage extraction unit 3 and the second-stage extraction unit 4 and the non-condensable steam mixture extracted from condenser 1 condense into steam condensate. After the condensate temperature in the tube side is increased, it is sent to the boiler section through the condensate outlet valve 14 for the next cycle;

[0036] S2, the working steam enters the first-stage extraction unit 3 through the power steam pipe 21. As the cross-sectional area of ​​the nozzle of the first-stage extraction unit 3 gradually decreases, the steam flow rate increases sharply and the pressure drops. When the pressure at the nozzle outlet is lower than the pressure inside the condenser 1, the non-condensable steam and a small amount of steam mixture in the condenser 1 are sucked into the mixing chamber in front of the nozzle through the non-condensable steam pipe 2. The sucked mixture is further mixed with the high-speed flowing working steam in the mixing chamber and pressurized and discharged. It enters the shell side of the first-stage extraction cooler 5. The mixed gas is cooled by the low-temperature condensate in the tube side. After the steam is condensed, it passes through the first-stage extraction unit condensate discharge pipe 11 and enters the hydrophobic expansion tank 2 under the influence of the potential difference. 4; the non-condensable steam in the shell side of the first-stage extraction cooler 5 is then sucked into the mixing chamber in front of the nozzle of the second-stage extraction cooler 4 through the valve of the second-stage extraction cooler air duct. Similar to the principle of the first-stage extraction cooler 3, the sucked mixture is further mixed with the high-speed flowing working steam in the mixing chamber of the second-stage extraction cooler 4, pressurized and discharged, and then enters the shell side of the second-stage extraction cooler 23. It continues to undergo a wall-type heat exchange with the condensate after heat exchange from the tube side of the first-stage extraction cooler 5. The shell side non-condensable steam and a small amount of steam mixture are cooled. After condensation, the steam passes through the first steam trap 32 and then through the first-stage extraction cooler condensate discharge pipe 12 to enter the steam expansion tank 24. The non-condensable steam is discharged into the atmosphere through the first vent pipe 35.

[0037] S3: The non-condensable steam and steam mixture passes through the non-condensable steam pipe 2, through the precooler air inlet valve 15, and into the shell side of the precooler 16. There, it exchanges heat with the circulating cooling water in the tube side through a partition wall. The steam in the mixture is condensed, and the steam condensate enters the hydrophobic expansion tank 24 through the precooler condensate pipe 25 by utilizing the potential difference. The non-condensable steam is then drawn into the oil ring vacuum pump 17 through the pipe. After mixing with the lubricating oil in the oil ring vacuum pump 17, it enters the separator 19 through the pipe. The non-condensable steam is discharged into the atmosphere through the second vent pipe 6. The separated vacuum lubricating oil enters the shell side of the afterheat exchanger 18 through the pipe. It exchanges heat with the circulating cooling water in the tube side through a partition wall. After the temperature is reduced, it enters the inlet of the oil ring vacuum pump 17 through the vacuum lubricating oil pipe 26 for the next cycle. By adjusting the circulating water volume in the tube side of the afterheat exchanger 18, the temperature of the lubricating oil entering the oil ring vacuum pump 17 is controlled between 35° C. and 38° C., thereby preventing the performance degradation of the lubricating oil due to long-term high temperature, which may cause shutdown.

[0038] Therefore, the present invention adopts the above-mentioned coal chemical driven steam turbine vacuum optimization energy-saving production device and method, and replaces the existing starting steam jet extraction mechanism by adding a direct extraction vacuum mechanism, namely an oil ring vacuum mechanism, to meet the two operating conditions before the turbine is started and during normal production. It operates in parallel with the original first-stage steam extractor and second-stage steam extractor, or operates alone, reducing the large amount of steam consumption and waste caused by the start-up of the steam jet extraction mechanism, and at the same time solving the problem of low condensation efficiency and poor vacuum operation caused by high temperature in summer, so as to achieve the purpose of stable production and energy saving and consumption reduction.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A coal chemical industry driven steam turbine vacuum optimization energy-saving production device, characterized by: It includes an exhaust condensation mechanism, a steam jet extraction mechanism and an oil ring vacuum mechanism. The exhaust condensation mechanism is connected to the steam jet extraction mechanism through a pipeline, the steam jet extraction mechanism is connected to the oil ring vacuum mechanism through a pipeline, and the oil ring vacuum mechanism is connected to the exhaust condensation mechanism through a pipeline.

2. The coal chemical industry driven steam turbine vacuum optimization energy-saving production device according to claim 1, characterized in that: The exhaust condensation mechanism includes a condenser, a drain expansion tank, a heat trap level gauge and a condensate pump. The drain expansion tank is communicated with the condenser. The condenser and the condensate pump are connected through a condensate pump inlet pipe. A heat trap level gauge is provided on one side of the heat trap at the bottom of the condenser. The condenser is provided with a turbine exhaust inlet pipe, a circulating water supply pipe and a circulating water return pipe. A condensate pump inlet valve is provided on the condensate pump inlet pipe.

3. The coal chemical industry driven steam turbine vacuum optimization energy-saving production device according to claim 2, characterized in that: The steam extraction mechanism includes a first-stage steam extraction unit, a second-stage steam extraction unit, a first-stage steam extraction cooler, a second-stage steam extraction cooler, a first-stage steam extraction unit air valve, a second-stage steam extraction unit air pipeline valve and a condensate outlet valve. A common pipe pass is provided between the first-stage steam extraction cooler and the second-stage steam extraction cooler. The condensate pump is connected to the common pipe pass through the steam extraction cooler inlet pipe. The common pipe pass is provided with a condensate outlet pipe. The shell side of the first-stage steam extraction cooler is connected to the hydrophobic expansion tank through the first-stage steam extraction unit condensate discharge pipe. The shell side of the second-stage steam extraction cooler is connected to the hydrophobic expansion tank through the second-stage steam extraction unit condensate discharge pipe. The shell side of the first-stage steam extraction cooler is connected to the first-stage steam extraction unit through a pipe. One end of the first-stage steam extraction unit is connected to the power steam pipeline, and the other end thereof is connected to the non-condensable steam pipeline. The shell side of the second-stage steam extraction cooler is connected to the second-stage steam extraction unit through a pipe. One end of the second-stage steam extraction unit is connected to the power steam pipeline, and the other end thereof is connected to the shell side of the first-stage steam extraction cooler through a pipe. The shell side of the second-stage steam extraction cooler is provided with a first vent pipe.

4. The coal chemical industry driven steam turbine vacuum optimization energy-saving production device according to claim 3, characterized in that: A condensate pump outlet valve is provided on the extraction cooler inlet pipe, a condensate discharge valve and a first steam trap are provided on the second-stage extraction cooler condensate discharge pipe near the second-stage extraction cooler, a first extraction valve is provided on the power steam pipe near the first-stage extraction pipe, and a second extraction valve is provided near the second-stage extraction pipe, a first-stage extraction air valve is provided on the non-condensing steam pipe near the first-stage extraction pipe, a second-stage extraction air pipe valve is provided on the pipe connecting the second-stage extraction pipe with the shell side of the first-stage extraction cooler, and a condensate delivery valve is provided on the condensate delivery pipe.

5. The coal chemical industry driven steam turbine vacuum optimization energy-saving production device according to claim 3, characterized in that: The oil ring vacuum mechanism includes a vacuum pressure gauge, a precooler air inlet valve, a precooler, a second steam trap, an oil ring vacuum pump, a separator, an afterheat exchanger and a temperature gauge. The condenser is connected to the precooler through a non-condensable steam pipe, the steam expansion tank is connected to the precooler through a precooler condensate pipe, the precooler is connected to the oil ring vacuum pump through a pipe, the oil ring vacuum pump is connected to the separator through a pipe, the separator is provided with a second vent pipe, the separator is connected to the afterheat exchanger through a pipe, the afterheat exchanger is connected to the oil ring vacuum pump through a vacuum lubricating oil pipe, and the precooler and the afterheat exchanger are both provided with circulating water supply and circulating water return.

6. The coal chemical industry driven steam turbine vacuum optimization energy-saving production device according to claim 5, characterized in that: A vacuum pressure gauge and a precooler air inlet valve are installed on the non-condensing steam pipeline, a second steam trap is installed on the precooler condensate pipeline, and a temperature gauge is installed on the vacuum lubricating oil pipeline.

7. The coal chemical industry driven steam turbine vacuum optimization energy-saving production device according to claim 4, characterized in that: The condensate delivery valve is connected to the hot trap level gauge through a cable.

8. A coal chemical industry driven steam turbine vacuum optimization energy-saving production method, characterized by: The coal chemical industry driven steam turbine vacuum optimization energy-saving production device according to any one of claims 1 to 7 comprises the following steps: S1: The exhaust steam and non-condensable steam from the steam turbine enter the shell side of the condenser, where they exchange heat with the circulating water wall in the tube side. The steam condenses and enters the heat sink at the bottom of the condenser. It then enters the condensate pump through the condensate pump inlet pipe. After the steam condensate is pressurized, it enters the common tube side through the extraction cooler inlet pipe. It then exchanges heat with the steam injected from the first and second extraction units in the shell side. The working steam from the first and second extraction units and the non-condensable steam extracted from the condenser condense into steam condensate. After the condensate temperature in the tube side is increased, it is sent to the boiler section through the condensate outlet valve for the next cycle. S2. The working steam enters the first-stage extraction unit through the power steam pipe. As the cross-sectional area of ​​the first-stage extraction unit nozzle gradually decreases, the steam flow rate increases sharply and the pressure drops. When the pressure at the nozzle outlet is lower than the pressure inside the condenser, the non-condensable steam and a small amount of steam mixture in the condenser are sucked into the mixing chamber in front of the nozzle through the non-condensable steam pipe. The sucked mixture is further mixed with the high-speed flowing working steam in the mixing chamber and discharged at a high pressure. It then enters the shell side of the first-stage extraction cooler. The mixed gas is cooled by the low-temperature condensate in the tube side. After condensation, the steam passes through the first-stage extraction unit condensate discharge pipe and enters the hydrophobic expansion chamber under the influence of the potential difference. The non-condensable steam in the shell side of the first-stage extraction cooler is then sucked into the mixing chamber in front of the nozzle of the second-stage extraction cooler through the valve of the air duct of the second-stage extraction cooler. The principle is the same as that of the first-stage extraction cooler. The sucked-in mixture is further mixed with the high-speed working steam in the mixing chamber of the second-stage extraction cooler and pressurized before being discharged. It then enters the shell side of the second-stage extraction cooler and continues to exchange heat with the condensate after heat exchange from the tube side of the first-stage extraction cooler. The mixture of the non-condensable steam in the shell side and a small amount of steam is cooled. After condensation, the steam passes through the first steam trap and the condensate discharge pipe of the second-stage extraction cooler into the steam trap expansion tank. The non-condensable steam is discharged into the atmosphere through the first vent pipe. S3. The non-condensable steam and steam mixture passes through the non-condensable steam pipeline and the air inlet valve of the precooler, and enters the shell side of the precooler, and exchanges heat with the circulating cooling water in the tube side. The steam in the mixture is condensed, and the steam condensate enters the hydrophobic expansion tank through the condensate pipeline of the precooler by utilizing the potential difference. The non-condensable steam is sucked into the oil ring vacuum pump through the pipeline, and after being mixed with the lubricating oil in the oil ring vacuum pump, it enters the separator through the pipeline. The non-condensable steam is discharged into the atmosphere through the second vent pipeline. The separated vacuum lubricating oil enters the shell side of the post-heat exchanger through the pipeline, and exchanges heat with the circulating cooling water in the tube side through the partition wall. After reducing the temperature, it enters the inlet of the oil ring vacuum pump through the vacuum lubricating oil pipeline for the next cycle.

9. The method for optimizing vacuum and energy-saving production of a coal chemical driven steam turbine according to claim 8, characterized in that: In S1, the vacuum index of the turbine condenser is controlled between -88kPa and -94kPa.

10. The method for vacuum optimization and energy-saving production of a coal chemical driven steam turbine according to claim 8, characterized in that: In S3, the temperature of the lubricating oil entering the oil ring vacuum pump is controlled between 35-38°C.

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