Steam turbine shaft seal heater device
By introducing a turbine shaft seal heater device into a gas-steam combined cycle unit, and using an electric heater to heat the steam, the thermal stress problem caused by excessive temperature difference at the rotor front shaft seal is solved, ensuring equipment safety and improving unit efficiency.
Patent Information
- Application Number
- CN202520509319.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2035-03-21
AI Technical Summary
In existing gas-steam combined cycle units, the steam temperature cannot exceed 200℃, resulting in an excessive temperature difference at the rotor front shaft seal, generating thermal stress, forming fatigue cracks, affecting equipment safety and reducing unit efficiency.
By introducing a turbine shaft seal heater device into a gas-steam combined cycle unit, the steam is heated by an electric heater to provide the required high-temperature steam for use at the turbine front shaft seal. This ensures that the rotor front shaft seal is not affected by thermal stress, avoids fatigue cracks, and guarantees equipment safety.
By introducing a turbine shaft seal heater device into the gas-steam combined cycle unit, low-temperature steam is heated by an electric heater to provide high-temperature steam that meets the requirements for use by the turbine front shaft seal. This ensures that the rotor front shaft seal is not affected by thermal stress, avoids fatigue cracks in the main shaft, and guarantees equipment safety.
Smart Images
Figure CN223754144U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of electric power production, specifically is a steam turbine shaft seal heater device. BACKGROUND
[0002] The existing gas-steam combined cycle unit is composed of a 123.4MW PG9171E type gas turbine, a double-pressure forced circulation waste heat boiler and a 60MW double-pressure condensing steam turbine, wherein the steam temperature when the equalizing box sends the shaft seal during the warm state and hot state start-up use of the machine room equipment cannot exceed 200 DEG C, resulting in that the temperature difference between the steam at the front shaft seal and the rotor reaches about 200 DEG C, due to the excessively large temperature difference, the front shaft seal of the rotor cannot be ensured from being affected by thermal stress, and then develops into a fatigue crack, threatening the safety of the equipment. Meanwhile, due to the long time that the temperature of the equalizing box cannot reach the shaft seal sending condition, the unit efficiency is greatly reduced. SUMMARY
[0003] The utility model discloses a steam turbine shaft seal heater device with remarkable energy-saving effect, high electric energy conversion efficiency, high efficiency heat conversion, electricity saving, longer service life, high reliability, reduced maintenance and replacement frequency.
[0004] The utility model is realized thus:
[0005] A steam turbine shaft seal heater device, including electric heater, the input of electric heater is connected with waste heat boiler, the waste heat boiler is connected with the input of electric heater and is connected with the inlet electric valve, the output of electric heater is connected with the equalizing box, and the output of electric heater is connected with the equalizing box and is connected with the outlet electric valve.
[0006] The electric heater includes a pry body, a plurality of "U"-shaped electric heating pipes are arranged in the pry body, a plurality of baffle plates are fixedly connected to the inner wall of the pry body, the baffle plates are connected with the electric heating pipes, the plurality of baffle plates are spirally and staggeredly arranged, and the input end and the output end of the electric heater are arranged at the left end and the right end of the pry body respectively.
[0007] Further, the heating body of the electric heating pipe is a Cr20Ni80 electric resistance alloy wire, and the insulator of the electric heating pipe 22 is high-temperature-resistant crystalline magnesium oxide powder.
[0008] Further, the input end of the electric heater is provided with an inlet temperature measuring end, and the output end of the electric heater is provided with an outlet temperature measuring end.
[0009] Further, the inlet electric valve and the waste heat boiler are provided with a shaft seal pressure regulating valve for regulating the steam pressure.
[0010] Further, a shaft seal steam isolation valve for steam isolation is arranged between the inlet electric valve and the waste heat boiler.
[0011] Further, a bypass electric valve is connected between the input end of the inlet electric valve and the output end of the outlet electric valve.
[0012] Further, a drain port is arranged on the pry body close to the output end of the electric heater, the drain port is connected to an atmospheric expansion vessel through an automatic drain valve, and the automatic drain valve is connected in parallel with an automatic drain bypass valve.
[0013] Compared with the prior art, the utility model has the beneficial effects that:
[0014] Through bypass modification, the external electric heater is fully utilized to heat low-temperature steam, high-temperature steam required for use before the shaft seal of the steam turbine is supplied, the front shaft seal of the rotor is ensured not to be affected by thermal stress, thereby avoiding large shaft fatigue cracks, ensuring equipment safety, and improving economic benefits. BRIEF DESCRIPTION OF DRAWINGS
[0015] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some embodiments of the utility model, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.
[0016] Figure 1 It is a schematic diagram of the pipeline of the utility model;
[0017] Figure 2 It is a schematic diagram of the partial section of the overall structure of the electric heater of the utility model.
[0018] The drawings are as follows: waste heat boiler 1, electric heater 2, pry body 21, electric heating pipe 22, baffle 23, inlet temperature measuring end 24, outlet temperature measuring end 25, drain port 26, inlet electric valve 3, outlet electric valve 4, equalizing tank 5, shaft seal pressure regulating valve 6, shaft seal steam isolation valve 7, bypass electric valve 8, automatic drain valve 9, automatic drain bypass valve 10. DETAILED DESCRIPTION
[0019] In order to make the purposes, technical schemes and advantages of the embodiments of the utility model clearer, the technical schemes in the embodiments of the utility model will be clearly and completely described in the following with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are some of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the utility model.
[0020] Please refer to Figure 1 and Figure 2 A steam turbine shaft seal heater device, including electric heater 2, the input end of electric heater 2 is connected with waste heat boiler 1, inlet electric valve 3 is connected between waste heat boiler 1 and the input end of electric heater 2, the output end of electric heater 2 is connected with pressure equalizing tank 5, outlet electric valve 4 is connected between the output end of electric heater 2 and pressure equalizing tank 5.
[0021] Electric heater 2 includes pry body 21, a plurality of "U"-shaped electric heating pipes 22 are arranged in pry body 21, a plurality of baffle plates 23 are fixedly connected to the inner wall of pry body 21, baffle plates 23 are connected with electric heating pipes 22, a plurality of baffle plates 23 are spirally staggered, and the input end and the output end of electric heater 2 are arranged at the left end and the right end of pry body 21 respectively.
[0022] The heating body of electric heating pipe 22 is Cr20Ni80 resistance alloy wire, and the insulator of electric heating pipe 22 is high-temperature-resistant crystalline magnesium oxide powder.
[0023] The input end of electric heater 2 is provided with inlet temperature measuring end 24, and the output end of electric heater 2 is provided with outlet temperature measuring end 25.
[0024] A shaft seal pressure regulating valve 6 for regulating steam pressure is arranged between inlet electric valve 3 and waste heat boiler 1.
[0025] A shaft seal steam supply isolation valve 7 for steam isolation is arranged between inlet electric valve 3 and waste heat boiler 1.
[0026] A bypass electric valve 8 is connected between the input end of inlet electric valve 3 and the output end of outlet electric valve 4.
[0027] The prying body 21 is provided with a discharge port 26 near the output end of the electric heater 2, the discharge port 26 is connected to an atmospheric expansion vessel through an automatic drain valve 9, and the automatic drain valve 9 is connected in parallel with an automatic drain bypass valve 10.
[0028] In practical application, please refer to Figure 1 and Figure 2 The waste heat boiler 1 outputs high-pressure steam meeting the pressure requirement to the electric heater 2 through a steam pipeline, in the process, the inlet electric valve 3 and the outlet electric valve 4 are opened, the bypass electric valve 8 is closed, the steam pressure is adjusted through the shaft seal pressure regulating valve 6, and the steam is isolated through the shaft seal steam supply isolation valve 7, the high-temperature steam enters the prying body 21 through the input end of the electric heater 2, is heated through a plurality of U-shaped electric heating pipes 22, the heating body of the electric heating pipe 22 is a Cr20Ni80 resistance alloy wire, and the insulator of the electric heating pipe 22 is high-purity high-temperature-resistant crystalline magnesium oxide powder, which is formed through a compression process to ensure the service life of the electric heating element, the electric heating pipe 22 is fixed through the baffle 23, and the fluid flow rate is accelerated to improve the heat transfer effect, the electric heater 2 has the characteristics of fast temperature rising speed, high temperature control precision, high thermal efficiency, safety monitoring device, convenient maintenance and the like, and the temperature of the steam less than 200 DEG C is raised to 380 DEG C to 450 DEG C; in the temperature rising process, the input temperature and the output temperature of the steam in the prying body 21 can be monitored through the inlet temperature measuring end 24 and the outlet temperature measuring end 25 respectively, the output temperature of the high-temperature steam is ensured to meet the requirement, when the input temperature meets the requirement, the bypass electric valve 8 is opened, and the inlet electric valve 3 is closed at the same time, so that the steam is directly sent into the pressure equalizing box 5; the high-temperature steam after being heated through the electric heater 2 is sequentially sent into the pressure equalizing box 5 through the output end of the electric heater and the outlet electric valve 4, and is used for the shaft seal before the steam turbine, so that the rotor front shaft seal is ensured not to be affected by thermal stress, thereby avoiding the fatigue crack of the large shaft and ensuring the safety of the equipment; after the electric heater 2 is out of operation, the residual high-temperature steam in the prying body 21 is condensed to form condensed water through temperature reduction, and the condensed water is sequentially discharged into the atmospheric expansion vessel through the discharge port 26, the automatic drain valve 9 or the automatic drain bypass valve 10, so that the problem that the condensed water is stored in the equipment for a long time and causes the equipment to vibrate when the equipment is operated under pressure is avoided.
[0029] The utility model has remarkable energy-saving effect, high electric energy conversion efficiency, can efficiently convert heat energy, save electricity fee, longer life, high reliability, reduce maintenance and replacement frequency.
[0030] The above only is the preferred implementation way of the utility model and is not used for limiting the utility model, for the person skilled in the art, the utility model can have various changes and changes. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the utility model should be included in the protection scope of the utility model.
Claims
1. A steam turbine shaft seal heater apparatus, characterized by: The electric heater (2) is connected with a waste heat boiler (1), an inlet electric valve (3) is connected between the waste heat boiler (1) and the input end of the electric heater (2), a pressure equalizing tank (5) is connected to the output end of the electric heater (2), and an outlet electric valve (4) is connected between the output end of the electric heater (2) and the pressure equalizing tank (5). The electric heater (2) comprises a pry body (21), a plurality of "U"-shaped electric heating pipes (22) are arranged in the pry body (21), a plurality of baffles (23) are fixedly connected to the inner wall of the pry body (21), the baffles (23) are connected with the electric heating pipes (22), the baffles (23) are spirally and staggeredly arranged, and the input end and the output end of the electric heater (2) are arranged at the left end and the right end of the pry body (21) respectively.
2. A steam turbine shaft seal heater apparatus as claimed in claim 1, wherein, The heating body of the electric heating pipe (22) is a Cr20Ni80 resistance alloy wire, and the insulator of the electric heating pipe (22) is high-temperature-resistant crystalline magnesium oxide powder.
3. A steam turbine shaft seal heater apparatus as claimed in claim 1, wherein, The input end of the electric heater (2) is provided with an inlet temperature measuring end (24), and the output end of the electric heater (2) is provided with an outlet temperature measuring end (25).
4. A steam turbine shaft seal heater apparatus as claimed in claim 1, wherein, A shaft seal pressure regulating valve (6) for regulating steam pressure is arranged between the inlet electric valve (3) and the waste heat boiler (1).
5. A steam turbine shaft seal heater apparatus as claimed in claim 1, wherein, A shaft seal steam supply isolation valve (7) for steam isolation is arranged between the inlet electric valve (3) and the waste heat boiler (1).
6. A steam turbine shaft seal heater apparatus as claimed in claim 1, wherein, A bypass electric valve (8) is connected between the input end of the inlet electric valve (3) and the output end of the outlet electric valve (4).
7. A steam turbine shaft seal heater apparatus as claimed in claim 1, wherein, A drain port (26) is arranged on the pry body (21) close to the output end of the electric heater (2), the drain port (26) is connected to an atmospheric expander through an automatic drain valve (9), and the automatic drain valve (9) is connected in parallel with an automatic drain bypass valve (10).