Load-reduction energy-saving adjustment industrial steam supply system with unit load lower limit limited by high-parameter large-scale steam consumption

Abstract

The invention discloses a load-reducing and energy-saving adjusting industrial steam supply system with a unit load lower limit limited by high-parameter large-scale steam consumption, belongs to the technical field of industrial steam supply systems, and aims to solve the problems that high-grade energy is wasted and energy consumption is low due to the fact that most of existing common load-reducing and industrial steam supply supplementing modes select unit high side steam or main steam as a steam source. In order to solve the problems that the requirements of large-scale steam consumption and power grid dispatching for the lower limit of unit load cannot be met at the same time, heat steam re-extraction is matched with middle linked gate parameter regulation, the steam supply mode can be flexibly switched according to different requirements of electric loads and heat loads, and the original industrial steam supply mode is adopted when the power generation load is high and the steam supply load is large; when the steam supply load is small, a heat and no-adjustment steam extraction mode is adopted; and a heat re-adjustable steam extraction mode is adopted in medium and low power generation loads and large steam supply loads. Finally, the unit can meet the steam demand under the high-parameter and large-scale extreme conditions of a heat user by using a heat source lower than the main steam grade, meanwhile, the safe operation of the unit is ensured, and the load is reduced to the power grid dispatching demand.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial steam supply systems, and in particular relates to an industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of unit load is restricted by high-parameter large-scale steam consumption. Background Art

[0002] The parameters of steam used in industrial production are generally higher than those used for heating, and the scale of steam consumption is huge during the heating season. When the unit is the only heat source for regional heating, in order to ensure the heating of the production and facilities of important users, it is necessary to ensure the stability of the heating pressure and flow. If the unit trips and the heating is interrupted during operation, it will have an immeasurable impact on important users and will seriously threaten the safe and stable operation of the production of important users and production facilities. Therefore, it generally does not participate in regional power grid dispatching, that is, the original design operating conditions of the unit do not take into account the steam supply requirements during deep adjustment.

[0003] However, in order to meet the needs of new energy development, during the heating season when industrial steam demand is high (peak 300-350 tons / hour, steam source pressure measurement requirement is above 1.2MPa), when the unit responds to grid dispatch and reduces load by less than 60%, on the one hand, it cannot guarantee the user's steam consumption and steam parameters, and on the other hand, some steam-using equipment in the unit's internal system also has the problem of affecting the overall safe and stable operation of the unit due to parameter reduction. At the same time, because the unit load cannot meet the grid dispatch requirements, it also faces high spot allocation and assessment costs;

[0004] The commonly used methods of reducing load and supplementing industrial steam supply currently use the unit's high bypass or main steam as the steam source, which results in high-grade energy waste and cannot meet the lower limit requirements of large-scale steam use and grid dispatching for unit load. Summary of the invention

[0005] The present invention aims to solve the problem that the commonly used methods of load reduction and industrial steam supplementation mostly use the unit high bypass or main steam as the steam source, resulting in high-grade energy waste and the inability to meet the requirements of large-scale steam consumption and power grid dispatching for the lower limit of the unit load; and further provides a load reduction and energy-saving adjustment industrial steam supply system in which the lower limit of the unit load is limited by high-parameter large-scale steam consumption;

[0006] An industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of unit load is limited by large-scale steam consumption with high parameters, the steam supply system comprises a steam turbine unit, the steam turbine unit comprises a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder, the steam supply system also comprises an original hot re-maining pipe, a hot re-extraction steam pipeline, a four-stage extraction steam internal steam supply pipeline, a four-stage extraction steam external steam supply pipeline, a hot re-extraction steam tee and a No. 1 interface tee, the original hot re-maining pipe is arranged on the steam inlet end of the intermediate-pressure cylinder and is connected to the intermediate-pressure cylinder, and the steam outlet end of the original hot re-maining pipe is connected to the steam turbine unit, the original hot re-maining pipe is provided with a hot re-extraction steam tee, and the steam inlet end of the hot re-extraction steam pipeline is connected to the original hot re The mother pipe is connected, the four-stage extraction steam internal steam supply pipeline and the four-stage extraction steam external steam supply pipeline are both arranged on the extraction end of the medium pressure cylinder, the steam inlet end of the four-stage extraction steam internal steam supply pipeline is connected with the extraction end of the medium pressure cylinder, the steam outlet end of the four-stage extraction steam internal steam supply pipeline is connected with the small steam turbine in the plant and the heater in the plant heat network, the steam inlet end of the four-stage extraction steam external steam supply pipeline is connected with the extraction end of the medium pressure cylinder, the steam outlet end of the four-stage extraction steam external steam supply pipeline is connected with the heat user outside the plant, a No. 1 interface tee is arranged on the four-stage extraction steam external steam supply pipeline, and the steam outlet end of the hot re-extraction steam pipeline is connected with the four-stage extraction steam external steam supply pipeline through the No. 1 interface tee;

[0007] Furthermore, a No. 1 pneumatic quick-closing valve, a pneumatic check valve, an electric gate valve, a temperature and pressure reducer, an electric butterfly valve and a hot re-extraction steam flow meter are sequentially connected in series on the hot re-extraction steam pipeline from the steam inlet end to the steam outlet end;

[0008] Furthermore, the four-stage steam extraction external steam supply pipeline is serially connected with an external steam supply pipeline electric regulating valve, an external steam supply pipeline pneumatic check valve, an external steam supply pipeline electric gate valve and an external steam supply pipeline desuperheater from the steam inlet end to the steam outlet end;

[0009] Furthermore, the four-stage steam extraction internal steam supply pipeline includes an internal small machine steam supply branch pipe and a heating network heating branch pipe, the steam inlet end of the internal small machine steam supply branch pipe is connected with the steam extraction end of the medium pressure cylinder, the steam outlet end of the internal small machine steam supply branch pipe is connected with the small steam turbine in the plant, the steam inlet end of the heating network heating branch pipe is connected with the internal small machine steam supply branch pipe through the heating network heater and the small machine flow diversion tee, and the steam outlet end of the heating network heating branch pipe is connected with the heating network heater in the plant;

[0010] Furthermore, the internal small machine steam supply branch pipe is sequentially connected in series with an internal steam supply pipeline pneumatic check valve, an internal steam supply pipeline pneumatic check valve and an internal steam supply pipeline electric gate valve from the steam inlet end to the steam outlet end;

[0011] The heating network heater and the small unit diversion tee are located between the electric gate valve of the internal steam supply pipeline and the small steam turbine in the plant;

[0012] The heating branch pipe of the heating network is connected in series with an electric gate valve of the steam supply pipe of the heating network heater;

[0013] Furthermore, a No. 1 central regulating valve is connected in series to the original hot reheating main pipe, the No. 1 central regulating valve is located between the steam turbine unit and the hot reheating steam extraction tee, and a No. 2 central regulating valve is connected in parallel to the No. 1 central regulating valve. The reheated steam passes through the original hot reheating main pipe and the No. 1 central regulating valve and the No. 2 central regulating valve and enters the intermediate pressure cylinder;

[0014] Furthermore, the steam supply system further comprises a supplementary steam pipeline, the steam inlet end of the supplementary steam pipeline is connected to the four-stage steam extraction external steam supply pipeline through a No. 1 supplementary steam interface tee, the steam outlet end of the supplementary steam pipeline is connected to the heating branch pipeline of the heat network through a No. 2 supplementary steam interface tee, and the supplementary steam pipeline is connected in series with a supplementary steam pipeline electric butterfly valve and a supplementary steam pipeline flow meter in sequence from the steam inlet end to the steam outlet end;

[0015] Furthermore, a newly added pneumatic fast pipe valve is connected in series with the heating branch pipe of the heating network heater steam supply pipe, and the newly added pneumatic fast pipe valve is located between the No. 2 steam supplement interface tee and the heating network heater and small machine diversion tee;

[0016] Furthermore, the steam supply system further comprises a supplementary steam pipeline, the steam inlet end of the supplementary steam pipeline is connected with the hot re-extraction steam pipeline through the No. 3 supplementary steam interface tee, the steam outlet end of the supplementary steam pipeline is connected with the internal small unit steam supply branch pipe through the No. 4 supplementary steam interface tee, and the supplementary steam pipeline is connected in series with a supplementary steam pipeline electric butterfly valve and a supplementary steam pipeline flow meter in sequence from the steam inlet end to the steam outlet end;

[0017] Furthermore, a No. 2 pneumatic quick-closing valve is connected in series on the internal steam supply pipeline of the four-stage steam extraction, and the No. 2 pneumatic quick-closing valve is located between the electric gate valve of the internal steam supply pipeline and the heating network heater and the small machine diversion tee.

[0018] The beneficial effects of this application compared to the prior art are as follows:

[0019] The present application provides an industrial steam supply system for load reduction and energy saving adjustment in which the lower load limit of a unit is restricted by high-parameter large-scale steam consumption. On the basis of retaining the original large-scale high-parameter industrial steam supply system, the steam supply mode can be flexibly switched according to different demands of electricity and heat loads. In the heating season with large industrial steam demand (peak value 300-350 tons / hour, steam source pressure requirement of more than 1.2MPa), the unit can be reduced from the restricted 60% load lower limit to 30%-40%. Ultimately, the unit can use a heat source lower than the main steam quality to adjust to meet the high-parameter and large-scale steam demand of heat users in extreme situations, while ensuring the safe operation of the unit and adapting to the load scheduling requirements of the power grid for units with the same capacity.

[0020] The present application provides a load-reducing and energy-saving industrial steam supply system whose lower load limit is limited by high-parameter and large-scale steam consumption. The system adopts hot re-extraction and coordinated with the Zhonglian gate parameter adjustment, so that the steam supply mode can be flexibly switched according to the different demands of electricity and heat loads. The original industrial steam supply mode is adopted for high power generation load and large steam supply load; the hot re-adjustable steam extraction mode is adopted for small steam supply load; the hot re-adjustable steam extraction mode is adopted for medium and low power generation load and large steam supply load. Ultimately, the unit can meet the steam demand of heat users under high parameters and large-scale extreme conditions by using heat sources lower than the main steam quality, while ensuring the safe operation of the unit and reducing the load to the grid dispatching demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a general diagram of the industrial steam supply system for load reduction and energy saving adjustment in which the lower load limit of the unit described in this application is limited by high-parameter large-scale steam consumption (specific implementation method one);

[0022] Figure 2 This is the general diagram of the industrial steam supply system for load reduction and energy saving adjustment in which the lower load limit of the unit described in this application is limited by high-parameter large-scale steam consumption (specific implementation method 2);

[0023] In the figure, 1 is the high-pressure cylinder, 2 is the medium-pressure cylinder, 3 is the low-pressure cylinder, 4 is the No. 1 center regulating valve, 5 is the No. 2 center regulating valve, 6 is the original hot re-extraction main pipe, 7 is the hot re-extraction steam tee, 8 is the No. 1 pneumatic fast closing valve, 9 is the pneumatic check valve, 10 is the electric gate valve, 11 is the temperature and pressure reducer, 12 is the electric butterfly valve, 13 is the hot re-extraction steam flow meter, 14 is the No. 1 interface tee, 15 is the No. 1 supplementary steam interface tee, 16 is the supplementary steam pipeline electric butterfly valve, 17 is the supplementary steam pipeline flow meter, 18 is the No. 2 supplementary steam interface tee, 19 is the external steam supply pipeline electric regulating valve, 20 is the external steam supply pipeline pneumatic check valve Valve, 21 electric gate valve for external steam supply pipeline, 22 desuperheater for external steam supply pipeline, 23 pneumatic check valve for internal steam supply pipeline, 24 pneumatic check valve for internal steam supply pipeline, 25 electric gate valve for internal steam supply pipeline, 26 diversion tee for heating network heater and small unit, 27 steam supply branch pipe for internal small unit, 28 heating network heating branch pipeline, 29 new pneumatic fast pipe valve for heating network heater steam supply pipeline, 30 electric gate valve for heating network heater steam supply pipeline, 31 No. 2 pneumatic fast closing valve, 32 No. 4 steam supply interface tee, 33 No. 3 steam supply interface tee. DETAILED DESCRIPTION

[0024] Specific implementation method 1: Combination Figure 1The present embodiment is described. In the present embodiment, there is provided an industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of the unit load is limited by large-scale steam consumption with high parameters. The steam supply system comprises a steam turbine unit, and the steam turbine unit comprises a high-pressure cylinder 1, an intermediate-pressure cylinder 2 and a low-pressure cylinder 3. The steam supply system also comprises an original hot re-extraction main pipe 6, a hot re-extraction steam pipeline, a four-stage steam extraction internal steam supply pipeline, a four-stage steam extraction external steam supply pipeline, a hot re-extraction steam tee 7 and a No. 1 interface tee 14. The original hot re-extraction main pipe 6 is arranged on the steam inlet end of the intermediate-pressure cylinder 2 and is connected to the intermediate-pressure cylinder 2, and the steam outlet end of the original hot re-extraction main pipe 6 is connected to the steam turbine unit. A hot re-extraction steam tee 7 is provided on the original hot re-extraction main pipe 6. The steam inlet end of the hot re-extraction steam pipeline is connected to the intermediate-pressure cylinder 2 through a hot The re-extraction tee 7 is connected with the original hot re-extraction mother pipe 6, the four-stage extraction steam internal steam supply pipeline and the four-stage extraction steam external steam supply pipeline are both arranged on the extraction end of the medium pressure cylinder 2, the steam inlet end of the four-stage extraction steam internal steam supply pipeline is connected with the extraction end of the medium pressure cylinder 2, the steam outlet end of the four-stage extraction steam internal steam supply pipeline is connected with the small steam turbine in the plant and the plant heat network heater, the steam inlet end of the four-stage extraction steam external steam supply pipeline is connected with the extraction end of the medium pressure cylinder 2, the steam outlet end of the four-stage extraction steam external steam supply pipeline is connected with the heat user outside the plant, the four-stage extraction steam external steam supply pipeline is provided with a No. 1 interface tee 14, and the steam outlet end of the hot re-extraction steam pipeline is connected with the four-stage extraction steam external steam supply pipeline through the No. 1 interface tee 14;

[0025] The hot re-extraction steam pipeline is connected in series from the steam inlet end to the steam outlet end in sequence: a pneumatic quick-closing valve 8, a pneumatic check valve 9, an electric gate valve 10, a temperature and pressure reducer 11, an electric butterfly valve 12 and a hot re-extraction steam flow meter 13;

[0026] The four-stage steam extraction external steam supply pipeline is connected in series from the steam inlet end to the steam outlet end with an external steam supply pipeline electric regulating valve 19, an external steam supply pipeline pneumatic check valve 20, an external steam supply pipeline electric gate valve 21 and an external steam supply pipeline desuperheater 22;

[0027] The four-stage extraction steam internal steam supply pipeline includes an internal small machine steam supply branch pipe 27 and a heating network heating branch pipe 28. The steam inlet end of the internal small machine steam supply branch pipe 27 is connected to the extraction end of the medium pressure cylinder 2, and the steam outlet end of the internal small machine steam supply branch pipe 27 is connected to the small steam turbine in the plant. The steam inlet end of the heating network heating branch pipe 28 is connected to the internal small machine steam supply branch pipe 27 through the heating network heater and the small machine flow diversion tee 26, and the steam outlet end of the heating network heating branch pipe 28 is connected to the heating network heater in the plant.

[0028] The internal steam supply branch pipe 27 is connected in series with an internal steam supply pipeline pneumatic check valve 23, an internal steam supply pipeline pneumatic check valve 24 and an internal steam supply pipeline electric gate valve 25 from the steam inlet end to the steam outlet end;

[0029] The heating network heater and the small machine diversion tee 26 are located between the electric gate valve 25 of the internal steam supply pipeline and the small steam turbine in the plant;

[0030] The heating branch pipe 28 of the heating network is connected in series with an electric gate valve 30 for the steam supply pipe of the heating network heater;

[0031] The original hot reheating main pipe 6 is connected in series with a No. 1 central regulating valve 4, which is located between the steam turbine unit and the hot reheating extraction tee 7. The No. 2 central regulating valve 5 is connected in parallel to the No. 1 central regulating valve 4. The reheated steam passes through the original hot reheating main pipe 6 and the No. 1 central regulating valve 4 and the No. 2 central regulating valve 5 and enters the intermediate pressure cylinder 2;

[0032] The steam supply system also includes a supplementary steam pipeline. The steam inlet end of the supplementary steam pipeline is connected to the four-stage steam extraction external steam supply pipeline through the No. 1 supplementary steam interface tee 15. The steam outlet end of the supplementary steam pipeline is connected to the heating network heating branch pipeline 28 through the No. 2 supplementary steam interface tee 18. The supplementary steam pipeline is connected in series with a supplementary steam pipeline electric butterfly valve 16 and a supplementary steam pipeline flow meter 17 from the steam inlet end to the steam outlet end.

[0033] A newly added pneumatic fast pipe valve 29 of the heating network heater steam supply pipeline is connected in series on the heating network heating branch pipeline 28. The newly added pneumatic fast pipe valve 29 of the heating network heater steam supply pipeline is located between the No. 2 steam supplementary interface tee 18 and the heating network heater and small unit diversion tee 26.

[0034] The present embodiment provides a load reduction and energy-saving adjustment industrial steam supply system in which the lower limit of the unit load is limited by high-parameter large-scale steam consumption. It is mainly aimed at regional single heat source units. In order to ensure the production and facility heating needs of important users, when the steam consumption scale is large and the parameters are high, the lower limit of the unit load cannot meet the peak-shaving needs of units with the same capacity and the stable operation of its own system (part of the pipeline is overheated or the small steam unit cannot operate normally), under the premise of ensuring the original steam supply mode, the appropriate quality heat source is used to cooperate with the supplementary steam supply, so that the unit can realize energy-saving and flexible adjustment of industrial steam supply according to the different matching requirements of heat load and electric load. The working principle of this application is described in three working conditions below;

[0035] Working condition 1: When the power generation load and steam supply load are high, the original industrial steam supply method is used:

[0036] When the power generation load and steam supply load are high, the original industrial steam supply method is adopted: after the four-stage extraction steam is extracted from the medium pressure cylinder, a part of it is supplied to the inside through the pneumatic check valve 23 of the internal steam supply pipeline, the pneumatic check valve 24 of the internal steam supply pipeline and the electric gate valve 25 of the internal steam supply pipeline to ensure the steam supply of small units and heating network heaters in the plant; the other part is supplied to the outside through the electric regulating valve 19 of the external steam supply pipeline, the pneumatic check valve 20 of the external steam supply pipeline, the electric gate valve 21 of the external steam supply pipeline and the desuperheater 22 of the external steam supply pipeline.

[0037] Working condition 2: When the steam supply load is small, the heat extraction method is adopted without adjusting the steam:

[0038] When the steam consumption is relatively small and the electric load needs to be appropriately reduced, it is led out through the hot re-extraction steam pipeline, and successively passes through the No. 1 pneumatic fast closing valve 8, the pneumatic check valve 9, the electric gate valve 10, the temperature reducing pressurizer 11, the electric butterfly valve 12, the hot re-extraction steam flow meter 13 and the No. 1 interface tee 14 to connect to the original four-stage steam extraction external steam supply pipeline. One part of it is supplied to the outside, and the other part is connected to the steam supply pipeline for the steam-using equipment in the factory through the No. 1 steam supply interface tee 15. The steam supply passes through the steam supply pipeline electric butterfly valve 1 6. The flow meter 17 of the supplementary steam pipeline and the No. 2 supplementary steam interface tee 18 are connected to the heating branch pipeline 28 of the heating network. In the non-heating season, the electric gate valve 30 of the heating network heater steam supply pipeline is closed. A pneumatic quick pipe valve 29, the heating branch pipeline 28 of the heating network and the tee 26 of the heating network heater and the small unit are added to the steam supply branch pipe 27 of the internal small unit through the heating network heater steam supply pipeline. In the heating season, it needs to be opened to supply steam to the heating network heater in the plant at the same time to ensure the safe and stable operation of the steam-using equipment in the plant when the power load is low;

[0039] Working condition 3: When the power generation load is low or medium and the steam supply load is large, the heat re-adjustable steam extraction method is adopted:

[0040] In this operating condition, on the basis of operating condition 2, the newly modified No. 1 central regulating valve 4 and No. 2 central regulating valve 5 are used to coordinate the adjustment to ensure the steam extraction volume, steam extraction parameters and unit steam inlet parameters, thereby ensuring the heat safety of heat users and the safety of unit operation.

[0041] Specific implementation method 2: Combination Figure 2 The present embodiment is described. In the present embodiment, there is provided an industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of the unit load is limited by large-scale steam consumption with high parameters. The steam supply system comprises a steam turbine unit, and the steam turbine unit comprises a high-pressure cylinder 1, an intermediate-pressure cylinder 2 and a low-pressure cylinder 3. The steam supply system also comprises an original hot re-extraction main pipe 6, a hot re-extraction steam pipeline, a four-stage steam extraction internal steam supply pipeline, a four-stage steam extraction external steam supply pipeline, a hot re-extraction steam tee 7 and a No. 1 interface tee 14. The original hot re-extraction main pipe 6 is arranged on the steam inlet end of the intermediate-pressure cylinder 2 and is connected to the intermediate-pressure cylinder 2, and the steam outlet end of the original hot re-extraction main pipe 6 is connected to the steam turbine unit. A hot re-extraction steam tee 7 is provided on the original hot re-extraction main pipe 6. The steam inlet end of the hot re-extraction steam pipeline is connected to the intermediate-pressure cylinder 2 through a hot The re-extraction tee 7 is connected with the original hot re-extraction mother pipe 6, the four-stage extraction steam internal steam supply pipeline and the four-stage extraction steam external steam supply pipeline are both arranged on the extraction end of the medium pressure cylinder 2, the steam inlet end of the four-stage extraction steam internal steam supply pipeline is connected with the extraction end of the medium pressure cylinder 2, the steam outlet end of the four-stage extraction steam internal steam supply pipeline is connected with the small steam turbine in the plant and the plant heat network heater, the steam inlet end of the four-stage extraction steam external steam supply pipeline is connected with the extraction end of the medium pressure cylinder 2, the steam outlet end of the four-stage extraction steam external steam supply pipeline is connected with the heat user outside the plant, the four-stage extraction steam external steam supply pipeline is provided with a No. 1 interface tee 14, and the steam outlet end of the hot re-extraction steam pipeline is connected with the four-stage extraction steam external steam supply pipeline through the No. 1 interface tee 14;

[0042] The hot re-extraction steam pipeline is connected in series from the steam inlet end to the steam outlet end in sequence: a pneumatic quick-closing valve 8, a pneumatic check valve 9, an electric gate valve 10, a temperature and pressure reducer 11, an electric butterfly valve 12 and a hot re-extraction steam flow meter 13;

[0043] On the four-stage steam extraction external steam supply pipeline, from the steam inlet end to the steam outlet end, an external steam supply pipeline electric regulating valve 19, an external steam supply pipeline pneumatic check valve 20, an external steam supply pipeline electric gate valve 21 and an external steam supply pipeline desuperheater 22 are connected in series in sequence;

[0044] The four-stage extraction steam internal steam supply pipeline includes an internal small machine steam supply branch pipe 27 and a heating network heating branch pipe 28. The steam inlet end of the internal small machine steam supply branch pipe 27 is connected to the extraction end of the medium pressure cylinder 2, and the steam outlet end of the internal small machine steam supply branch pipe 27 is connected to the small steam turbine in the plant. The steam inlet end of the heating network heating branch pipe 28 is connected to the internal small machine steam supply branch pipe 27 through the heating network heater and the small machine flow diversion tee 26, and the steam outlet end of the heating network heating branch pipe 28 is connected to the heating network heater in the plant.

[0045] The internal steam supply branch pipe 27 is connected in series with an internal steam supply pipeline pneumatic check valve 23, an internal steam supply pipeline pneumatic check valve 24 and an internal steam supply pipeline electric gate valve 25 from the steam inlet end to the steam outlet end;

[0046] The heating network heater and the small machine diversion tee 26 are located between the electric gate valve 25 of the internal steam supply pipeline and the small steam turbine in the plant;

[0047] The heating branch pipe 28 of the heating network is connected in series with an electric gate valve 30 for the steam supply pipe of the heating network heater;

[0048] The original hot reheating main pipe 6 is connected in series with a No. 1 central regulating valve 4, which is located between the steam turbine unit and the hot reheating extraction tee 7. The No. 2 central regulating valve 5 is connected in parallel to the No. 1 central regulating valve 4. The reheated steam passes through the original hot reheating main pipe 6 and the No. 1 central regulating valve 4 and the No. 2 central regulating valve 5 and enters the intermediate pressure cylinder 2;

[0049] The steam supply system also includes a supplementary steam pipeline, the steam inlet end of the supplementary steam pipeline is connected to the hot re-extraction steam pipeline through the No. 3 supplementary steam interface tee 33, and the steam outlet end of the supplementary steam pipeline is connected to the internal small unit steam supply branch pipe 27 through the No. 4 supplementary steam interface tee 32. The supplementary steam pipeline is connected in series with a supplementary steam pipeline electric butterfly valve 16 and a supplementary steam pipeline flow meter 17 from the steam inlet end to the steam outlet end;

[0050] A No. 2 pneumatic quick-closing valve 31 is connected in series on the internal steam supply pipeline of the four-stage steam extraction, and the No. 2 pneumatic quick-closing valve 31 is located between the electric gate valve 25 of the internal steam supply pipeline and the heat network heater and small machine diversion tee 26.

[0051] In the present embodiment, a load reduction and energy-saving adjustment industrial steam supply system is provided in which the lower limit of the unit load is limited by large-scale steam consumption with high parameters. The working principle is similar to that of the specific embodiment 1, except that the arrangement position of the supplementary steam pipeline is different. The design scheme provided in the present embodiment is to adjust the arrangement position of the No. 2 supplementary steam interface tee 18 and the newly added pneumatic fast pipe valve 29 of the steam supply pipeline of the heating network heater in the specific embodiment 1 when the original external steam supply pipeline is not used for supplementary steam, remove the No. 2 supplementary steam interface tee 18 and add a No. 4 supplementary steam interface tee 32, remove the newly added pneumatic fast pipe valve 29 of the steam supply pipeline of the heating network heater and add a No. 2 pneumatic fast closing valve 31, and the hot re-extraction steam is connected to the original plant area four-stage steam extraction steam supply pipeline for small machines through the No. 4 supplementary steam interface tee 32, and enters the plant area heating network heater through the internal small machine steam supply branch pipe 27, the heating network heater and small machine diversion tee 26, the heating network heating branch pipeline 28 and the heating network heater steam supply pipeline electric gate valve 30 in the heating network heater.

Claims

1. An industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of the unit load is limited by large-scale steam consumption with high parameters, the steam supply system comprises a steam turbine unit, the steam turbine unit comprises a high-pressure cylinder (1), an intermediate-pressure cylinder (2) and a low-pressure cylinder (3), and is characterized in that: The steam supply system also includes an original hot re-extraction main pipe (6), a hot re-extraction steam pipeline, a four-stage steam extraction internal steam supply pipeline, a four-stage steam extraction external steam supply pipeline, a hot re-extraction steam tee (7) and a No. 1 interface tee (14). The original hot re-extraction main pipe (6) is arranged on the steam inlet end of the intermediate pressure cylinder (2) and is connected to the intermediate pressure cylinder (2), and the steam outlet end of the original hot re-extraction main pipe (6) is connected to the steam turbine unit. The original hot re-extraction main pipe (6) is provided with a hot re-extraction steam tee (7). The steam inlet end of the hot re-extraction steam pipeline is connected to the original hot re-extraction main pipe (6) through the hot re-extraction steam tee (7). The four-stage steam extraction internal steam supply pipeline and the four-stage steam extraction external steam supply pipeline are connected to the steam turbine unit. The external steam supply pipelines are all arranged on the extraction end of the medium pressure cylinder (2); the steam inlet end of the four-stage extraction steam internal steam supply pipeline is connected to the extraction end of the medium pressure cylinder (2); the steam outlet end of the four-stage extraction steam internal steam supply pipeline is connected to the small steam turbine and the plant heat network heater; the steam inlet end of the four-stage extraction steam external steam supply pipeline is connected to the extraction end of the medium pressure cylinder (2); the steam outlet end of the four-stage extraction steam external steam supply pipeline is connected to the heat user outside the plant; a No. 1 interface tee (14) is provided on the four-stage extraction steam external steam supply pipeline; and the steam outlet end of the hot re-extraction steam pipeline is connected to the four-stage extraction steam external steam supply pipeline through the No. 1 interface tee (14).

2. According to claim 1, a load reduction and energy-saving adjustment industrial steam supply system with a unit load lower limit limited by high-parameter large-scale steam consumption, characterized in that: A pneumatic quick-closing valve (8), a pneumatic check valve (9), an electric gate valve (10), a temperature and pressure reducer (11), an electric butterfly valve (12) and a hot re-extraction steam flow meter (13) are sequentially connected in series on the hot re-extraction steam pipeline from the steam inlet end to the steam outlet end.

3. According to claim 2, a load reduction and energy-saving adjustment industrial steam supply system with a unit load lower limit limited by high-parameter large-scale steam consumption is characterized by: The four-stage steam extraction external steam supply pipeline is serially connected with an external steam supply pipeline electric regulating valve (19), an external steam supply pipeline pneumatic check valve (20), an external steam supply pipeline electric gate valve (21) and an external steam supply pipeline desuperheater (22) in sequence from the steam inlet end to the steam outlet end.

4. According to claim 3, a load reduction and energy-saving adjustment industrial steam supply system with a unit load lower limit limited by high-parameter large-scale steam consumption is characterized in that: The four-stage steam extraction internal steam supply pipeline comprises an internal small machine steam supply branch pipe (27) and a heating network heating branch pipe (28). The steam inlet end of the internal small machine steam supply branch pipe (27) is connected to the steam extraction end of the medium pressure cylinder (2), and the steam outlet end of the internal small machine steam supply branch pipe (27) is connected to the small steam turbine in the plant. The steam inlet end of the heating network heating branch pipe (28) is connected to the internal small machine steam supply branch pipe (27) through the heating network heater and the small machine flow dividing tee (26), and the steam outlet end of the heating network heating branch pipe (28) is connected to the heating network heater in the plant.

5. According to claim 4, a load reduction and energy-saving adjustment industrial steam supply system with a unit load lower limit limited by high-parameter large-scale steam consumption is characterized by: The internal small machine steam supply branch pipe (27) is sequentially connected in series with an internal steam supply pipeline pneumatic check valve (23), an internal steam supply pipeline pneumatic check valve (24) and an internal steam supply pipeline electric gate valve (25) from the steam inlet end to the steam outlet end; The heating network heater and the small turbine diversion tee (26) are located between the electric gate valve (25) of the internal steam supply pipeline and the small steam turbine in the plant; The heating network heating branch pipeline (28) is connected in series with an electric gate valve (30) for the steam supply pipeline of the heating network heater.

6. According to claim 5, a load reduction and energy-saving adjustment industrial steam supply system with a unit load lower limit limited by high-parameter large-scale steam consumption is characterized by: A No. 1 central regulating valve (4) is connected in series to the original hot reheating main pipe (6). The No. 1 central regulating valve (4) is located between the steam turbine unit and the hot reheating extraction tee (7). A No. 2 central regulating valve (5) is connected in parallel to the No. 1 central regulating valve (4). The reheated steam passes through the original hot reheating main pipe (6) and the No. 1 central regulating valve (4) and the No. 2 central regulating valve (5) and enters the intermediate pressure cylinder (2).

7. The industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of unit load is limited by large-scale steam consumption with high parameters according to claim 6 is characterized in that: The steam supply system also includes a supplementary steam pipeline. The steam inlet end of the supplementary steam pipeline is connected to the four-stage steam extraction external steam supply pipeline through a No. 1 supplementary steam interface tee (15). The steam outlet end of the supplementary steam pipeline is connected to the heating network heating branch pipeline (28) through a No. 2 supplementary steam interface tee (18). The supplementary steam pipeline is connected in series with a supplementary steam pipeline electric butterfly valve (16) and a supplementary steam pipeline flow meter (17) from the steam inlet end to the steam outlet end.

8. The industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of unit load is limited by large-scale steam consumption with high parameters according to claim 7 is characterized in that: A newly added pneumatic quick pipe valve (29) for the steam supply pipeline of the heating network heater is connected in series on the heating network heating branch pipeline (28). The newly added pneumatic quick pipe valve (29) for the steam supply pipeline of the heating network heater is located between the No. 2 steam supplement interface tee (18) and the heating network heater and small machine diversion tee (26).

9. The industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of unit load is limited by large-scale steam consumption with high parameters according to claim 6 is characterized in that: The steam supply system also includes a supplementary steam pipeline. The steam inlet end of the supplementary steam pipeline is connected to the hot re-extraction steam pipeline through a No. 3 supplementary steam interface tee (33). The steam outlet end of the supplementary steam pipeline is connected to the internal small unit steam supply branch pipe (27) through a No. 4 supplementary steam interface tee (32). The supplementary steam pipeline is connected in series with a supplementary steam pipeline electric butterfly valve (16) and a supplementary steam pipeline flow meter (17) from the steam inlet end to the steam outlet end.

10. The industrial steam supply system for load reduction and energy saving adjustment in which the lower limit of unit load is limited by large-scale steam consumption with high parameters according to claim 9 is characterized in that: A No. 2 pneumatic quick-closing valve (31) is connected in series on the internal steam supply pipeline of the four-stage steam extraction, and the No. 2 pneumatic quick-closing valve (31) is located between the electric gate valve (25) of the internal steam supply pipeline and the heat network heater and small machine diversion tee (26).

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