CN215949594U - Secondary reheating steam turbine and matched double-machine regenerative system - Google Patents

Abstract

A novel 1000MW grade secondary reheating 630 ℃ steam turbine and a matched double-machine regenerative system. In particular to a steam turbine and a double-machine regenerative system. The utility model aims to solve the problems that the loss of a regenerative system exergy is increased, so that the performance gain of the steam turbine caused by the improvement of steam parameters is influenced, the manufacturing cost is greatly improved, and the high-temperature application risk of a high-pressure heater is aggravated in the conventional double reheating steam turbine. A novel 1000MW grade double reheating 630 ℃ steam turbine and a matched double-machine regenerative system comprise a double-machine regenerative system and a steam turbine; a double-machine regenerative system is matched and applied to the steam turbine; the double-machine heat regeneration system is respectively connected with the ultrahigh pressure module, the medium pressure module, the first low pressure module and the second low pressure module through pipelines, and the connection mode of the first low pressure module and the connection mode of the second low pressure module are the same as that of the double-machine heat regeneration system. The method can be used for a secondary reheating thermal power project with steam parameters of 630 ℃ in 1000MW grade.

Description

Secondary reheating steam turbine and matched double-machine regenerative system

Technical Field

The utility model relates to the technical field of steam turbines and double-machine regenerative systems, in particular to a secondary reheating steam turbine and a matched double-machine regenerative system.

Background

The main steam temperature curing parameter of the existing double reheat steam turbine is 600-605 ℃, the reheat temperature curing parameter is 620-622 ℃, and the design of an intermediate-stage parameter level steam turbine and the research and study demonstration of system innovation and application are urgently needed to be carried out in the technical development of the application field of ultrahigh steam parameters, so that the breakthrough of the power generation efficiency of a power station is realized, and a national coal-electricity clean and efficient sustainable energy development layout is created; in addition conventional parameter secondary reheat steam turbine is conventional backheat system design, the extraction steam of through-flow intermediate level can influence steam flow efficiency in the through-flow, 630 ℃ admission temperature high pressure and middling pressure extraction steam all have great steam superheat degree, backheat system exergy loss increases, thereby influence the steam turbine performance income that steam parameter promotes and bring, boiler owner is the reheat steam pipe way simultaneously, backheat extraction steam pipe way and high pressure feed water heater also promote by a wide margin because of temperature promotion cost, and aggravate high temperature application risk of high pressure feed water heater, wait to carry out corresponding backheat system innovation design urgently.

In conclusion, the conventional double reheat steam turbine has the problems that the loss of the heat recovery system exergy is increased, so that the performance gain of the steam turbine caused by the improvement of steam parameters is influenced, the manufacturing cost is greatly improved, and the high-temperature application risk of a high-pressure heater is aggravated.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problems that the loss of a regenerative system exergy is increased, so that the performance gain of the steam turbine caused by the improvement of steam parameters is influenced, the manufacturing cost is greatly improved, and the high-temperature application risk of a high-pressure heater is aggravated in the conventional double reheating steam turbine. Further provides a double reheating steam turbine and a matched double-machine reheating system.

The technical scheme of the utility model is as follows:

a double reheating steam turbine and a matched double-machine regenerative system comprise a steam turbine and a double-machine regenerative system;

a double-machine regenerative system is matched and applied to the steam turbine;

the steam turbine comprises an ultrahigh pressure module, a high pressure module, a medium pressure module, a first low pressure module, a second low pressure module, a first bearing box, a second bearing box, a third bearing box, a fourth bearing box, a fifth bearing box, a sixth bearing box, a plurality of centering beams and a plurality of lower cylinder catpaws;

the adjusting end of the ultrahigh pressure module is fixedly connected with the first bearing box through a centering beam, the electric end of the ultrahigh pressure module is fixedly connected with one end of the second bearing box through the centering beam, the other end of the second bearing box is fixedly connected with the adjusting end of the high pressure module through the centering beam, the electric end of the high pressure module is in sliding contact with one end of the third bearing box through a lower cylinder cat claw, the other end of the third bearing box is in sliding contact with the adjusting end of the medium pressure module through the lower cylinder cat claw, the electric end of the medium pressure module is fixedly connected with one end of the fourth bearing box through the centering beam, the other end of the fourth bearing box is fixedly connected with the adjusting end of the first low pressure module, the electric end of the first low pressure module is fixedly connected with one end of the fifth bearing box, the other end of the fifth bearing box is fixedly connected with the adjusting end of the second low pressure module, and the electric end of the second low pressure module is fixedly connected with one end of the sixth bearing box, the other end of the bearing box II is fixedly connected with a generator;

the double-machine heat regeneration system is respectively connected with the ultrahigh pressure module, the medium pressure module, the first low pressure module and the second low pressure module through pipelines, and the connection mode of the first low pressure module and the connection mode of the second low pressure module are the same as that of the double-machine heat regeneration system.

Compared with the prior art, the utility model discloses a secondary reheating steam turbine and a matched double-machine regenerative system, which has the following effects:

the utility model relates to a double reheating turbine and a matched double-machine regenerative system, wherein an ultrahigh pressure module, a high pressure module, a medium pressure module, a first low pressure module, a second low pressure module, a first bearing box, a second bearing box, a third bearing box, a fourth bearing box, a fifth bearing box, a sixth bearing box and a generator form a whole machine, the whole machine is suitable for the design of steam inlet parameters of 35MPa/615 ℃/630 ℃/630 ℃, the heat consumption of the whole machine design is improved by the initial parameters of the turbine, the circulating heat efficiency is obviously improved, the reliability, the safety and the stability of long-term application of 630 ℃ steam parameters are ensured, meanwhile, the performance of the turbine is obviously improved by the steam parameters, and the flow efficiency of the steam inside the high pressure module and the medium pressure module of the turbine and the circulating efficiency of the steam regenerative system (optimizing regenerative stages and reducing regenerative steam extraction quality) can be further improved by applying the double-machine regenerative system, the high-pressure heater, boiler reheat steam pipeline cost and high temperature risk are reduced, and the main cycle steam turbine drives the feed pump operation simultaneously, and operating efficiency is higher than conventional feed pump steam turbine. The development and breakthrough of power generation technologies such as 650 ℃ and 700 ℃ steam parameter engineering steam turbine material model selection, body structure design, thermodynamic system innovation application and the like can be promoted through the design and application of the utility model of the main steam turbine and the regenerative system. The utility model aims to solve the problems that in the prior art, the double reheat steam turbines are all designed by a conventional regenerative system, the flow efficiency of steam in through flow is influenced by steam extraction of a through flow middle stage, the high-pressure steam extraction and the medium-pressure steam extraction both have larger steam superheat degree at the steam inlet temperature of 630 ℃, the loss of the regenerative system exergy is increased, so that the performance gain of the steam turbine caused by steam parameter improvement is influenced, the manufacturing cost of a main reheat steam pipeline, a regenerative steam extraction pipeline and a high-pressure heater is greatly increased due to temperature improvement, and the high-temperature application risk of the high-pressure heater is aggravated.

Drawings

FIG. 1 is a front view of a steam turbine of the present invention;

FIG. 2 is a top plan view of the steam turbine of the present invention;

FIG. 3 is a schematic longitudinal cross-sectional view of the steam turbine of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 at A;

FIG. 5 is an enlarged view of a portion of FIG. 3 at B;

FIG. 6 is an enlarged view of a portion of FIG. 3 at C;

fig. 7 is a schematic diagram of a dual-turbine regenerative system and a steam turbine according to the present invention.

Detailed Description

The first embodiment is as follows: the present embodiment is described with reference to fig. 1 to 7, and a secondary reheating turbine and a matched dual-turbine regenerative system of the present embodiment include a turbine and a dual-turbine regenerative system;

a double-machine regenerative system is matched and applied to the steam turbine;

the steam turbine comprises an ultrahigh pressure module 1, a high pressure module 2, a medium pressure module 3, a first low pressure module 4, a second low pressure module 5, a first bearing box 6, a second bearing box 7, a third bearing box 8, a fourth bearing box 9, a fifth bearing box 10, a sixth bearing box 11, a plurality of centering beams and a plurality of lower cylinder catpaws;

the adjusting end of the ultrahigh pressure module 1 is fixedly connected with the first bearing box 6 through a centering beam, the electric end of the ultrahigh pressure module 1 is fixedly connected with one end of the second bearing box 7 through a centering beam, the other end of the second bearing box 7 is fixedly connected with the adjusting end of the high pressure module 2 through a centering beam, the electric end of the high pressure module 2 is in sliding contact with one end of the third bearing box 8 through a lower cylinder claw, the other end of the third bearing box 8 is in sliding contact with the adjusting end of the medium pressure module 3 through a lower cylinder claw, the electric end of the medium pressure module 3 is fixedly connected with one end of the fourth bearing box 9 through a centering beam, the other end of the fourth bearing box 9 is fixedly connected with the adjusting end of the first low pressure module 4, the electric end of the first low pressure module 4 is fixedly connected with one end of the fifth bearing box 10, the other end of the fifth bearing box 10 is fixedly connected with the adjusting end of the second low pressure module 5, the electric end of the second low pressure module 5 is fixedly connected with one end of the sixth bearing box 11, the other end of the bearing box II 11 is fixedly connected with a generator 12;

the double-machine regenerative system is respectively connected with the ultrahigh pressure module 1, the medium pressure module 3, the first low pressure module 4 and the second low pressure module 5 through pipelines, and the connection mode of the first low pressure module 4 and the second low pressure module 5 is the same as that of the double-machine regenerative system.

According to the arrangement, the ultrahigh pressure module 1 and the high pressure module 2 are symmetrically arranged in a single flow mode, the ultrahigh pressure rotors 1-6 and the high pressure rotors 2-6 are provided with ultrahigh pressure balance drum steam seals 1-5 and high pressure balance drum steam seals 2-5, the ultrahigh pressure balance drum steam seals 1-5 and the high pressure balance drum steam seals 2-5 are designed by adopting a single-cylinder self-balancing thrust system, the ultrahigh pressure module 1 and the high pressure module 2 are symmetrically arranged in a single flow mode, and are more beneficial to balancing of the thrust of the whole machine under the variable working condition, the medium pressure module 3, the first low pressure module 4 and the second low pressure module 5 are in double flow, and the thrust is self-balancing.

The second embodiment is as follows: this embodiment will be described with reference to fig. 7, which shows

The double-machine regenerative system comprises a first unit regenerative system and a second unit regenerative system;

the first unit heat recovery system comprises a condenser 11-3, a condenser steam inlet pipeline 11-4, a condensate pump, a steam seal cooler, a No. 9 low-pressure heater 11-5, a No. 9 low-pressure heater steam extraction pipeline 11-6, a No. 10 low-pressure heater 11-7, a No. 10 low-pressure heater steam extraction pipeline 11-8, a No. 11 low-pressure heater 11-9, a No. 11 low-pressure heater steam extraction pipeline 11-10, a No. 12 low-pressure heater 11-11 and a No. 12 low-pressure heater steam extraction pipeline 11-12;

the first low-pressure module 4 is connected with the No. 9 low-pressure heater 11-5 through a No. 9 low-pressure heater steam extraction pipeline 11-6, the first low-pressure module 4 is connected with the No. 10 low-pressure heater 11-7 through a No. 10 low-pressure heater steam extraction pipeline 11-8, the first low-pressure module 4 is connected with the No. 11 low-pressure heater 11-9 through a No. 11 low-pressure heater steam extraction pipeline 11-10, the first low-pressure module 4 is connected with the No. 12 low-pressure heater 11-11 through a No. 12 low-pressure heater steam extraction pipeline 11-12, the first low-pressure module 4 is connected with the condenser 11-3 through a condenser steam inlet pipeline 11-4, the No. 9 low-pressure heater 11-5, the No. 10 low-pressure heater 11-7, the No. 11 low-9 and the No. 12 low-pressure heater 11-11, The steam seal cooler and the condenser 11-3 are sequentially connected from right to left along the length direction of the double-machine regenerative system, the No. 12 low-pressure heater 11-11, the condensate pump, the steam seal cooler and the condenser 11-3 are connected, and the No. 12 low-pressure heater 11-11 is connected with the condenser 11-3 through a pipeline.

The second unit regenerative system comprises a main circulation water-feeding pump turbine 11-1, a main circulation water-feeding pump turbine steam inlet pipeline 11-2, a first high-pressure heater 11-13, a first high-pressure heater steam extraction pipeline 11-14, a second high-pressure heater 11-15, a second high-pressure heater steam extraction pipeline 11-16, a third high-pressure heater 11-17, a third high-pressure heater steam extraction pipeline 11-18, a fourth high-pressure heater 11-19, a fourth high-pressure heater steam extraction pipeline 11-20, a fifth high-pressure heater 11-21, a fifth high-pressure heater steam extraction pipeline 11-22, a deaerator 11-23, a deaerator steam extraction pipeline 11-24, a seventh low-pressure heater 11-25, a main circulation water-feeding pump turbine steam extraction pipeline 11-26, an overflow regulating valve 11-27, a seventh low-pressure heater 11-25, a main circulation water-feeding pump turbine steam extraction pipeline 11-26, and an overflow regulating valve 11-27, Overflow pipelines 11-28 and a No. eight low-pressure heater 11-29;

the ultrahigh pressure module 1 is connected with a main circulation water feeding pump turbine 11-1 through a main circulation water feeding pump turbine steam inlet pipeline 11-2, the ultrahigh pressure module 1 is connected with a first high pressure heater 11-13 through an ultrahigh pressure exhaust pipeline in the ultrahigh pressure module 1, the main circulation water feeding pump turbine 11-1 is respectively connected with a second high pressure heater steam extraction pipeline 11-16, a third high pressure heater steam extraction pipeline 11-18, a fourth high pressure heater steam extraction pipeline 11-20, a fifth high pressure heater steam extraction pipeline 11-22, a deaerator steam extraction pipeline 11-24, a main circulation water feeding pump turbine steam exhaust pipeline 11-26, an overflow pipeline 11-28 and a second high pressure heater 11-15, a third high pressure heater 11-17, a fourth high pressure heater 11-19, a third high pressure heater 11-18, a fourth high pressure heater 11-13, a fourth high pressure heater 11-24, a fourth high pressure heater 11-2, a fourth high pressure heater 11-13, a fourth high pressure heater, a high pressure heater, The fifth high-pressure heater 11-21, the deaerator 11-23, the seventh low-pressure heater 11-25 and the overflow regulating valve 11-27 are connected, the overflow regulating valve 11-27 is connected with the eighth low-pressure heater 11-29 through an overflow pipeline 11-28, the middle-pressure module 3 is connected with the eighth low-pressure heater 11-29 through a middle-pressure exhaust pipeline in the middle-pressure module 3, the first high-pressure heater 11-13 is connected with a boiler through a first high-pressure heater steam extraction pipeline 11-14, the first high-pressure heater 11-13, the second high-pressure heater 11-15, the third high-pressure heater 11-17, the fourth high-pressure heater 11-19, the fifth high-pressure heater 11-21, the deaerator 11-23, the seventh low-pressure heater 11-25, the eighth low-pressure heater 11-29 and the 9 low-pressure heater 11-5 are sequentially connected from right to left along the length direction of the double-machine heat recovery system And (6) connecting.

The rest is the same as the first embodiment.

The third concrete implementation mode: the embodiment is described with reference to fig. 1 to 3, and the embodiment further includes two ultrahigh-pressure main steam adjusting and steam supplementing combined valves 13, two high-pressure main steam adjusting combined valves 14, and two medium-pressure main steam adjusting combined valves 15;

the two ultrahigh pressure main steam adjusting and supplementing combined valves 13 are symmetrically arranged on two sides of the ultrahigh pressure module 1 respectively, the two high pressure main steam adjusting combined valves 14 are symmetrically arranged on the high pressure module 2 and symmetrically arranged on two sides of the ultrahigh pressure module 1 respectively, and the two medium pressure main steam adjusting combined valves 15 are symmetrically arranged on two sides of the medium pressure module 3 respectively.

The arrangement is that two ultrahigh pressure main steam adjusting and steam supplementing combined valves 13, two high pressure main steam adjusting combined valves 14 and two medium pressure main steam adjusting combined valves 15 have no steam guide pipe structure and are rigidly and directly connected with the cylinder. The others are the same as in the first or second embodiment.

The fourth concrete implementation mode: the present embodiment is described with reference to fig. 1 to 3, and the ultrahigh pressure module 1 of the present embodiment includes an ultrahigh pressure outer cylinder 1-1, an ultrahigh pressure inner cylinder 1-2, an ultrahigh pressure exhaust side end gland seal 1-3, an ultrahigh pressure intake side end gland seal 1-4, an ultrahigh pressure balance drum gland seal 1-5, an ultrahigh pressure rotor 1-6, ultrahigh pressure moving blades, and ultrahigh pressure stationary blades;

the ultrahigh pressure inner cylinder 1-2 is arranged in the ultrahigh pressure outer cylinder 1-1, the ultrahigh pressure rotor 1-6 is arranged in the horizontal center of the ultrahigh pressure inner cylinder 1-2, the ultrahigh pressure steam exhaust side end steam seal 1-3 is assembled at the adjusting end of the ultrahigh pressure outer cylinder 1-1, the ultrahigh pressure steam inlet side end steam seal 1-4 is assembled at the electric end of the ultrahigh pressure outer cylinder 1-1, the ultrahigh pressure balance drum steam seal 1-5 is assembled at the electric end of the ultrahigh pressure inner cylinder 1-2, and the ultrahigh pressure moving blades and the ultrahigh pressure static blades are respectively assembled on the ultrahigh pressure rotor 1-6 and the ultrahigh pressure inner cylinder 1-2.

The ultrahigh pressure module 1 adopts a 2 multiplied by 180-degree tangential volute steam inlet structure, so that the pressure loss of steam at the inlet position of the cylinder body can be effectively reduced, and the steam kinetic energy conversion efficiency is improved. The others are the same as any one of the first to third embodiments.

The fifth concrete implementation mode: the embodiment is described with reference to fig. 3, and the high-pressure module 2 of the embodiment comprises a high-pressure outer cylinder 2-1, a high-pressure inner cylinder 2-2, a high-pressure steam-exhaust side end steam seal 2-3, a high-pressure steam-intake side end steam seal 2-4, a high-pressure balance drum steam seal 2-5, a high-pressure rotor 2-6, high-pressure moving blades and high-pressure static blades;

the high-pressure inner cylinder 2-2 is arranged inside the high-pressure outer cylinder 2-1, the high-pressure rotor 2-6 is arranged in the horizontal center inside the high-pressure inner cylinder 2-2 and is arranged concentrically with the ultrahigh-pressure rotor 1-6, the high-pressure steam inlet side end steam seal 2-4 is assembled at the adjusting end of the high-pressure outer cylinder 2-1, the high-pressure steam outlet side end steam seal 2-3 is assembled at the electric end of the high-pressure outer cylinder 2-1, the high-pressure balance drum steam seal 2-5 is assembled at the adjusting end of the high-pressure outer cylinder 2-1, and the high-pressure moving blades and the high-pressure static blades are respectively assembled on the high-pressure rotor 2-6 and the high-pressure inner cylinder 2-2.

The arrangement is that the high-pressure module 2 adopts a 2 multiplied by 180-degree tangential volute steam inlet structure, so that the pressure loss of steam at the inlet position of the cylinder body can be effectively reduced, and the steam kinetic energy conversion efficiency is improved. The rest is the same as any one of the first to fourth embodiments.

The sixth specific implementation mode: the embodiment is described with reference to fig. 3, and the intermediate pressure module 3 of the embodiment includes an intermediate pressure outer cylinder 3-1, an intermediate pressure inner cylinder 3-2, two intermediate pressure exhaust side end steam seals 3-3, an intermediate pressure rotor 3-4, intermediate pressure positive direction moving blades and intermediate pressure positive direction stationary blades;

the middle-pressure inner cylinder 3-2 is arranged inside the middle-pressure outer cylinder 3-1, the middle-pressure rotor 3-4 is arranged in the horizontal center inside the middle-pressure inner cylinder 3-2, the middle-pressure rotor 3-4 is concentrically arranged with the ultrahigh-pressure rotor 1-6 and the high-pressure rotor 2-6, one middle-pressure steam exhaust side end steam seal 3-3 is arranged at the adjusting end of the middle-pressure outer cylinder 3-1, the other middle-pressure steam exhaust side end steam seal 3-3 is arranged at the electric end of the middle-pressure outer cylinder 3-1, and middle-pressure positive direction moving blades and middle-pressure positive direction static blades are respectively assembled on the middle-pressure rotor 3-4 and the middle-pressure inner cylinder 3-2.

The middle-pressure rotor adopts a welding structure, so that the adaptability of the steam temperature of 630 ℃ can be effectively improved, and the reliability and the safety of the application can be effectively improved. The arrangement is that the medium-pressure module 3 adopts a 2X 180-degree tangential volute steam inlet structure, so that the pressure loss of steam at the inlet position of the cylinder body can be effectively reduced, and the steam kinetic energy conversion efficiency is improved. The rest is the same as any one of the first to fifth embodiments.

The seventh embodiment: the present embodiment is described with reference to fig. 3, and the first low pressure module 4 and the second low pressure module 5 of the present embodiment have the same structure;

the first low-pressure module 4 comprises a low-pressure outer cylinder 4-1, a low-pressure inner cylinder 4-2, two low-pressure steam exhaust side end steam seals 4-3, two end corrugated sections 4-4, a low-pressure rotor 4-5, low-pressure square moving blades, low-pressure square stationary blades and a partition plate sleeve;

the low-pressure inner cylinder 4-2 is arranged inside the low-pressure outer cylinder 4-1, the low-pressure rotor 4-5 is arranged inside the low-pressure inner cylinder 4-2, a low-pressure exhaust side steam seal 4-3 and an end corrugated joint 4-4 are sequentially arranged at the adjusting end of the low-pressure outer cylinder 4-1, the other end corrugated joint 4-4 and a low-pressure exhaust side steam seal 4-3 are sequentially arranged at the electric end of the low-pressure outer cylinder 4-1, and low-pressure square moving blades and low-pressure square static blades are respectively assembled on the low-pressure rotor 4-5, the low-pressure inner cylinder and the partition plate sleeve.

According to the arrangement, the low-pressure module 4 adopts a 360-degree volute steam inlet type low-pressure integral cast iron inner cylinder, the rigidity is good, the deformation is small, steam leakage loss caused by mid-split deformation can be avoided, the pressure loss of an inlet position can be effectively reduced by volute steam inlet, the efficiency of the low-pressure cylinder is improved, the low-pressure inner cylinder 4-2 is located at an outer cylinder supporting foot on the foundation through a supporting arm, namely the low-pressure inner cylinder 4-2 adopts a floor type structure, so that the low-pressure inner cylinder is more suitable for large-range vacuum change and steam exhaust temperature change, and the accurate centering of a rotor and a stator component can be ensured forever. The rest is the same as any one of the first to sixth embodiments.

The specific implementation mode is eight: the present embodiment is described with reference to fig. 3, which further includes a medium-low pressure communication pipe 16,

the middle and low pressure communicating pipe 16 is arranged right above the middle pressure module 3, the fourth bearing box 9, the first low pressure module 4, the fifth bearing box 10 and the second low pressure module 5;

the middle-low pressure communicating pipe 16 comprises a first connecting pipe 16-1, a second connecting pipe 16-2, a third connecting pipe 16-3, a fourth connecting pipe 16-4 and a straight pipe 16-5;

the first connecting pipe 16-1, the second connecting pipe 16-2, the third connecting pipe 16-3, the fourth connecting pipe 16-4 and the straight pipe 16-5 are integrated;

the first connecting pipe 16-1, the second connecting pipe 16-2, the third connecting pipe 16-3 and the fourth connecting pipe 16-4 are all arranged below the straight pipe 16-5, the first connecting pipe 16-1 is connected with the adjusting end of the medium-pressure outer cylinder 3-1 and communicated with the adjusting end of the medium-pressure outer cylinder 3-1, the second connecting pipe 16-2 is connected with the electric end of the medium-pressure outer cylinder 3-1 and communicated with the electric end of the medium-pressure outer cylinder 3-1, the third connecting pipe 16-3 is connected with the middle of the low-pressure outer cylinder 4-1 and communicated with the low-pressure outer cylinder, and the fourth connecting pipe 16-4 is connected with the middle of the low-pressure outer cylinder of the second low-pressure module 5 and communicated with the low-pressure outer cylinder.

The rest is the same as any one of the first to seventh embodiments.

The specific implementation method nine: referring to fig. 1 to 3, the steam turbine of the present embodiment further includes a thrust bearing,

the thrust bearing is arranged on the second bearing box 7, and the absolute dead points are respectively positioned at the intersection points of the transverse positioning key and the longitudinal positioning key at the middle part of the first low-voltage module 4, the middle part of the second low-voltage module 5 and the bottom of the third bearing box 8.

According to the arrangement, the first bearing box 6, the second bearing box 7, the third bearing box 8, the fourth bearing box 9, the fifth bearing box 10 and the sixth bearing box 11 are supported on the base frame through floor structures, the adjusting ends and the electric ends of the ultrahigh-pressure outer cylinder 1-1 and the high-pressure outer cylinder 2-1 are supported on the first bearing box 6, the second bearing box 7 and the third bearing box 8 through lower claws respectively, the ultrahigh-pressure outer cylinder 1-1 and the high-pressure outer cylinder 2-1 are axially fixed with the bearing boxes through centering beam push-pull mechanisms, the stress positions of the shafting boxes are changed to reduce the acting force of cylinder bodies on the bearing boxes, and the ultrahigh-pressure cylinder, the high-pressure cylinder, the first bearing box 6 and the second bearing box 7 expand towards the handpiece direction together by taking the third bearing box 8 as an absolute dead point. The adjusting end and the electric end of the middle-pressure outer cylinder 3-1 are respectively supported on a third bearing box 8 and a fourth bearing box 9 through lower cat claws, the middle-pressure outer cylinder 3-1 is axially fixed with the bearing boxes by adopting a centering beam push-pull mechanism, the middle-pressure outer cylinder 3-1 and the fourth bearing box 9 are expanded towards the electric end of the middle-pressure outer cylinder 3-1 by taking the third bearing box 8 as an absolute dead point, the first low-voltage module 4 and the second low-voltage module 5 are respectively expanded towards the electric end and the adjusting end by taking dead points of the first low-voltage module 4 and the second low-voltage module 5, a thrust bearing is arranged on the second bearing box 7, the ultrahigh-pressure rotor 1-6 is expanded towards the adjusting end, namely the machine head direction, and the low-pressure rotors 2-6, the middle-pressure rotor 3-4, the low-pressure rotor 4-5 and the second low-voltage module 5 are expanded towards the electric end direction by taking the thrust bearing as a base point. The others are the same as any one of the first to eighth embodiments.

The detailed implementation mode is ten: referring to fig. 1 to 3, the present embodiment is described, and the ultrahigh pressure module 1 and the high pressure module 2 of the present embodiment both adopt a 2 × 180 ° tangential volute steam inlet structure, and are provided with horizontal stationary vanes to ensure steam inlet efficiency. The ultrahigh pressure module 1 and the high pressure module 2 both adopt a double-layer cylinder structure, and the ultrahigh pressure inner cylinder 1-2 and the high pressure inner cylinder 2-2 both adopt regular cylindrical structures, so that the structure is simple and compact, the expansion is uniform, the thermal stress is small, and the quick start and stop of a unit and the variable load adaptation requirements are facilitated. The ultrahigh pressure inner cylinder 1-2 and the high pressure inner cylinder 2-2 are both in a shrink ring sealing mode, the steam parameter design with higher pressure and temperature is suitable, the sealing performance is good, the assembly in a modularized factory is realized, the whole product is delivered to the site, the strength check exceeds 20 ten thousand hours, and the 10-year overhaul period can be met. The rest is the same as any one of the first to ninth embodiments.

The concrete implementation mode eleven: the embodiment is described with reference to fig. 1 to 3, the medium-pressure module 3 of the embodiment adopts a 2 × 180 ° tangential volute steam inlet structure, and a double-cylinder, symmetrical split-flow design, the double-cylinder structure can effectively reduce the working temperature of the outer cylinder, save high-temperature resistant materials and control the expansion amount of the outer cylinder, and meanwhile, an annular steam inlet chamber is conveniently arranged, and double split-flow can effectively reduce the height of the last stage blade of the medium-pressure cylinder, and improve the application maturity of the blade. The others are the same as any one of the first to tenth embodiments.

The specific implementation mode twelve: the embodiment is described by combining fig. 1 to fig. 3, the first low-pressure module 4 and the second low-pressure module 5 of the embodiment adopt a 360-degree volute steam inlet type low-pressure integral cast iron inner cylinder, the rigidity is good, the deformation is small, steam leakage loss caused by mid-split deformation is avoided, the volute steam inlet can effectively reduce pressure loss at an inlet position, the efficiency of the low-pressure cylinder is improved, the inner cylinder is located at an outer cylinder supporting foot on a foundation through a supporting arm, namely the inner cylinder adopts a floor type structure, so that the inner cylinder is more suitable for large-scale vacuum change and steam exhaust temperature change, and the accurate centering of a rotor and a stator component can be ensured forever. The rest is the same as any one of the first to eleventh embodiments.

The specific implementation mode is thirteen: the embodiment is described with reference to fig. 1, and the low pressure rotors of the ultrahigh pressure rotors 1 to 6, the high pressure rotors 2 to 6, the low pressure rotors 4 to 5 and the second low pressure module 5 of the embodiment are all integrally forged rotors; the middle pressure rotor 3-4 adopts an improved FB2+2.25Cr welding structure, the middle of the middle pressure rotor 3-4 is made of an improved FB2 material, two ends of the middle pressure rotor 3-4 are made of 2.25Cr materials, the middle pressure rotor has different mechanical strength performances, the design is matched with the steam inlet temperature of 630 ℃, and the application safety and the reliability are higher. The rest is the same as any one of the first to twelfth embodiments.

The specific implementation mode is fourteen: the embodiment is described with reference to fig. 1 to 3, and the through flow of the ultra-high pressure module 1, the high pressure module 2 and the medium pressure module 3 of the embodiment is subjected to full three-dimensional pneumatic optimization design according to steam inlet parameters, and multi-stage reaction type through flow selection and high-efficiency wide-load post-loading blade profile application are provided with blade profile end wall optimization to improve the through flow pneumatic efficiency and variable load adaptive characteristics. Except the last two-stage baffle of low pressure, all the quiet leaf of all the other superhigh pressure module 1, high-pressure module 2, middling pressure module 3, a low pressure module 4 and No. two low pressure modules 5, movable vane adopt the pre-twist fabricated structure, compare with traditional welding baffle, the fabricated structure does not have the welding seam, the through-flow deformation of having avoided welding and the thermal treatment production after the welding, through-flow machining precision is higher, no operation welding thermal stress release, it is better to keep the effect for a long time, the unit rate of aging reduces. The rest is the same as any one of the first to thirteenth embodiments.

The concrete implementation mode is fifteen: the embodiment is described with reference to fig. 1 to 3, and the ultra-high voltage module 1, the high voltage module 2 and the medium voltage module 3 of the embodiment all adopt an N +1 bearing support mode, so that the length of a shaft system is shortened, the total length of a unit is shortened to the greatest extent on the premise of ensuring high cycle efficiency and high safety of the unit, the floor area of the unit is reduced, the field space is saved, and the infrastructure cost of a power station is reduced. The rest is the same as any one of the first to fourteenth embodiments.

The specific implementation mode is sixteen: the embodiment is described by combining fig. 1 to fig. 3, the ultrahigh pressure module 1, the high pressure module 2, the medium pressure module 3, the first low pressure module 4 and the second low pressure module 5 of the embodiment all adopt a volute steam inlet technology, the valve is directly connected with the elastic support, the additional force on the cylinder is small, the valve adopts an excellent diffusion opening flow channel design and is matched with a speed reduction type volute flow channel, the circumferential uniformity of the steam is improved to the maximum extent, the flow loss of the steam at an inlet position is reduced, the steam pressure drop is avoided from occurring outside the through flow, and the steam kinetic energy conversion efficiency is improved. The rest is the same as any one of the first to fifteenth embodiments.

Seventeenth embodiment: the present embodiment is described with reference to fig. 1 to 3, the through-flow middle stage of the ultra-high pressure module 1, the high pressure module 2, and the medium pressure module 3 of the present embodiment does not need to be designed with regenerative steam extraction, the flow efficiency of steam in the through-flow is higher, and the efficiency of the ultra-high pressure module 1, the high pressure module 2, and the medium pressure module 3 can be further improved. Meanwhile, a first-stage high-pressure heater and a first-stage low-pressure heater are optimized and added, the superheat degree of each stage of regenerative extraction steam is reduced, an external steam cooler can be omitted, and the circulation efficiency of a turbine thermodynamic system is remarkably improved. The design efficiency of the main circulation steam turbine is far higher than that of a conventional feed pump steam turbine, and meanwhile, the boiler reheater pipeline material consumption and the regenerative system cost are saved. The rest is the same as any one of the first to sixteenth embodiments.

The working principle is as follows:

the main steam of the steam turbine enters a reverse-flow ultrahigh pressure reverse-acting pressure level through an inlet steam valve of an ultrahigh pressure module 1 from an outlet of a boiler superheater, after acting, the main steam enters a primary reheater through a steam outlet on the lower half of an ultrahigh pressure outer cylinder 1-1, the steam after primary reheating enters a forward-flow high pressure cylinder reverse-acting pressure level through an inlet steam valve of a high pressure module 2, after acting, the steam enters a secondary reheater through a steam outlet on the lower half of the high pressure outer cylinder 2-1, the steam after secondary reheating enters a part of a medium pressure module 3 through two high pressure main steam adjusting joint valves 14 and two medium pressure main steam adjusting joint valves 15 arranged on two sides of the medium pressure module 3, flows through the forward and reverse-acting medium pressure level through-flow, after acting, the steam leaves the medium pressure outer cylinder 3-1 through an outlet on the upper half of the medium pressure outer cylinder 3-1, and the outlet is respectively connected with a first low pressure module 4 and a second low pressure module 5 through a medium and low pressure communicating pipe 16, respectively enters two completely same first low-pressure modules 4 and second low-pressure modules 5, enters a condenser 11-3 from the exhaust steam ports at the lower parts of exhaust cylinders of the first low-pressure modules 4 and the second low-pressure modules 5 after low-pressure through-flow, part of exhaust steam of an ultrahigh-pressure module 1 enters a main circulation water-feeding pump turbine 11-1 through a main circulation water-feeding pump turbine steam inlet pipeline 11-2, part of the main steam is extracted from the rear part of a through-flow 3 pressure stages and enters a second high-pressure heater 11-15 through a second high-pressure heater steam extraction pipeline 11-16, part of the steam is extracted from the rear part of the main stream after passing through 4 pressure stages and enters a third high-pressure heater 11-17 through a third high-pressure heater steam extraction pipeline 11-18, and part of the steam is extracted from the rear part of the main stream after passing through 4 pressure stages and enters a fourth high-pressure heater 11-19 through a fourth high-pressure heater steam extraction pipeline 11-20, and part of the steam is extracted after passing through 5 pressure stages and enters a fifth high-pressure heater 11-21 through a fifth high-pressure heater steam extraction pipeline 11-22, part of the steam is extracted after passing through 5 pressure stages and enters a deaerator 11-23 through a deaerator steam extraction pipeline 11-24, the steam is discharged out of a main circulation water feeding pump turbine 11-1 after passing through 4 pressure stages, part of the discharged steam enters a seventh low-pressure heater 11-25 through a main circulation water feeding pump turbine steam discharge pipeline 11-26, and the rest of the overflow steam enters an eighth low-pressure heater 11-29 through an overflow pipeline 11-28.

The present invention has been described in terms of the preferred embodiments, but it is not limited thereto, and any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention will still fall within the technical scope of the present invention.

Claims (9)

1. The utility model provides a double reheat steam turbine and supporting duplex backheating system which characterized in that: the system comprises a steam turbine and a double-machine regenerative system;

a double-machine regenerative system is matched and applied to the steam turbine;

the steam turbine comprises an ultrahigh pressure module (1), a high pressure module (2), a medium pressure module (3), a first low pressure module (4), a second low pressure module (5), a first bearing box (6), a second bearing box (7), a third bearing box (8), a fourth bearing box (9), a fifth bearing box (10), a sixth bearing box (11), a plurality of centering beams and a plurality of lower cylinder catclaws;

the adjusting end of the ultrahigh pressure module (1) is fixedly connected with the first bearing box (6) through a centering beam, the electric end of the ultrahigh pressure module (1) is fixedly connected with one end of the second bearing box (7) through the centering beam, the other end of the second bearing box (7) is fixedly connected with the adjusting end of the high pressure module (2) through the centering beam, the electric end of the high pressure module (2) is in sliding contact with one end of the third bearing box (8) through a lower cylinder cat claw, the other end of the third bearing box (8) is in sliding contact with the adjusting end of the medium pressure module (3) through a lower cylinder cat claw, the electric end of the medium pressure module (3) is fixedly connected with one end of the fourth bearing box (9) through the centering beam, the other end of the fourth bearing box (9) is fixedly connected with the adjusting end of the first low pressure module (4), the electric end of the first low pressure module (4) is fixedly connected with one end of the fifth bearing box (10), the other end of the fifth bearing box (10) is fixedly connected with the adjusting end of the second low-voltage module (5), the electric end of the second low-voltage module (5) is fixedly connected with one end of the sixth bearing box (11), and the other end of the sixth bearing box (11) is fixedly connected with the generator (12);

the double-machine heat regenerative system is respectively connected with the ultrahigh pressure module (1), the medium pressure module (3), the first low pressure module (4) and the second low pressure module (5) through pipelines, and the connection mode of the first low pressure module (4) and the second low pressure module (5) is the same as that of the double-machine heat regenerative system.

2. The double reheat steam turbine and the matched double heat recovery system of claim 1, wherein: the double-machine regenerative system comprises a first unit regenerative system and a second unit regenerative system;

the first unit heat recovery system comprises a condenser (11-3), a condenser steam inlet pipeline (11-4), a condensate pump, a steam seal cooler, a No. 9 low-pressure heater (11-5), a No. 9 low-pressure heater steam extraction pipeline (11-6), a No. 10 low-pressure heater (11-7), a No. 10 low-pressure heater steam extraction pipeline (11-8), a No. 11 low-pressure heater (11-9), a No. 11 low-pressure heater steam extraction pipeline (11-10), a No. 12 low-pressure heater (11-11) and a No. 12 low-pressure heater steam extraction pipeline (11-12);

the first low-pressure module (4) is connected with the No. 9 low-pressure heater (11-5) through a No. 9 low-pressure heater steam extraction pipeline (11-6), the first low-pressure module (4) is connected with the No. 10 low-pressure heater (11-7) through a No. 10 low-pressure heater steam extraction pipeline (11-8), the first low-pressure module (4) is connected with the No. 11 low-pressure heater (11-9) through a No. 11 low-pressure heater steam extraction pipeline (11-10), the first low-pressure module (4) is connected with the No. 12 low-pressure heater (11-11) through a No. 12 low-pressure heater steam extraction pipeline (11-12), the first low-pressure module (4) is connected with the condenser (11-3) through a condenser steam inlet pipeline (11-4), the No. 9 low-pressure heater (11-5), the No. 10 low-pressure heater (11-7), The No. 11 low-pressure heater (11-9), the No. 12 low-pressure heater (11-11), the steam seal cooler and the condenser (11-3) are sequentially connected from right to left along the length direction of the double-unit regenerative system, the No. 12 low-pressure heater (11-11), the condensate pump, the steam seal cooler and the condenser (11-3) are connected, and the No. 12 low-pressure heater (11-11) is connected with the condenser (11-3) through a pipeline;

the second unit regenerative system comprises a main circulation water-feeding pump turbine (11-1), a main circulation water-feeding pump turbine steam inlet pipeline (11-2), a first high-pressure heater (11-13), a first high-pressure heater steam extraction pipeline (11-14), a second high-pressure heater (11-15), a second high-pressure heater steam extraction pipeline (11-16), a third high-pressure heater (11-17), a third high-pressure heater steam extraction pipeline (11-18), a fourth high-pressure heater (11-19), a fourth high-pressure heater steam extraction pipeline (11-20), a fifth high-pressure heater (11-21), a fifth high-pressure heater steam extraction pipeline (11-22), a deaerator (11-23), a deaerator steam extraction pipeline (11-24), a seventh low-pressure heater (11-25), The system comprises main circulation water feeding pump steam turbine steam exhaust pipelines (11-26), overflow regulating valves (11-27), overflow pipelines (11-28) and No. eight low-pressure heaters (11-29);

the ultrahigh pressure module (1) is connected with a main circulation water feeding pump steam turbine (11-1) through a main circulation water feeding pump steam turbine steam inlet pipeline (11-2), the ultrahigh pressure module (1) is connected with a first high pressure heater (11-13) through an ultrahigh pressure exhaust pipeline in the ultrahigh pressure module (1), the main circulation water feeding pump steam turbine (11-1) is respectively connected with a deaerator steam extraction pipeline (11-24), a main circulation water feeding pump steam turbine exhaust pipeline (11-26), an overflow pipeline (11-28) and a second high pressure heater (11-15) corresponding to the deaerator steam extraction pipeline (11-24), the main circulation water feeding pump steam turbine exhaust pipeline (11-26), A third high-pressure heater (11-17), a fourth high-pressure heater (11-19), a fifth high-pressure heater (11-21), a deaerator (11-23), a seventh low-pressure heater (11-25) and an overflow regulating valve (11-27), wherein the overflow regulating valve (11-27) is connected with an eighth low-pressure heater (11-29) through an overflow pipeline (11-28), a medium-pressure module (3) is connected with the eighth low-pressure heater (11-29) through a medium-pressure exhaust pipeline in the medium-pressure module (3), a first high-pressure heater (11-13)11-13 is connected with a boiler through a first high-pressure heater steam extraction pipeline (11-14), a first high-pressure heater (11-13), a second high-pressure heater (11-15), a third high-pressure heater (11-17), The fourth high-pressure heater (11-19), the fifth high-pressure heater (11-21), the deaerator (11-23), the seventh low-pressure heater (11-25), the eighth low-pressure heater (11-29) and the 9 low-pressure heater (11-5) are sequentially connected from right to left along the length direction of the double-machine regenerative system.

3. The double reheat steam turbine and the matched double heat recovery system of claim 1, wherein: the system also comprises two ultrahigh pressure main steam adjusting and supplementing combined valves (13), two high pressure main steam adjusting combined valves (14) and two medium pressure main steam adjusting combined valves (15);

the two ultrahigh pressure main steam adjusting and steam supplementing combined valves (13) are symmetrically arranged on two sides of the ultrahigh pressure module (1) respectively, the two high pressure main steam adjusting combined valves (14) are symmetrically arranged on two sides of the high pressure module (2) symmetrically arranged on the ultrahigh pressure module (1) respectively, and the two medium pressure main steam adjusting combined valves (15) are symmetrically arranged on two sides of the medium pressure module (3) respectively.

4. The double reheat steam turbine and the matched double heat recovery system of claim 1, wherein: the ultrahigh pressure module (1) comprises an ultrahigh pressure outer cylinder (1-1), an ultrahigh pressure inner cylinder (1-2), an ultrahigh pressure steam exhaust side end steam seal (1-3), an ultrahigh pressure steam inlet side end steam seal (1-4), an ultrahigh pressure balance drum steam seal (1-5), ultrahigh pressure rotors (1-6), ultrahigh pressure moving blades and ultrahigh pressure stationary blades;

the ultrahigh pressure inner cylinder (1-2) is arranged in the ultrahigh pressure outer cylinder (1-1), the ultrahigh pressure rotor (1-6) is arranged in the horizontal center of the inside of the ultrahigh pressure inner cylinder (1-2), the ultrahigh pressure steam exhaust side end steam seal (1-3) is assembled at the adjusting end of the ultrahigh pressure outer cylinder (1-1), the ultrahigh pressure steam inlet side end steam seal (1-4) is assembled at the electric end of the ultrahigh pressure outer cylinder (1-1), the ultrahigh pressure balance drum steam seal (1-5) is assembled at the electric end of the ultrahigh pressure inner cylinder (1-2), and the ultrahigh pressure moving blades and the ultrahigh pressure static blades are respectively assembled on the ultrahigh pressure rotor (1-6) and the ultrahigh pressure inner cylinder (1-2).

5. The double reheat steam turbine and the matched double heat recovery system of claim 1, wherein: the high-pressure module (2) comprises a high-pressure outer cylinder (2-1), a high-pressure inner cylinder (2-2), a high-pressure steam exhaust side end steam seal (2-3), a high-pressure steam inlet side end steam seal (2-4), a high-pressure balance drum steam seal (2-5), a high-pressure rotor (2-6), high-pressure moving blades and high-pressure static blades;

the high-pressure inner cylinder (2-2) is arranged inside the high-pressure outer cylinder (2-1), the high-pressure rotor (2-6) is arranged in the horizontal center inside the high-pressure inner cylinder (2-2) and is concentrically arranged with the ultrahigh-pressure rotor (1-6), the high-pressure steam inlet side end steam seal (2-4) is assembled at the adjusting end of the high-pressure outer cylinder (2-1), the high-pressure steam exhaust side end steam seal (2-3) is assembled at the electric end of the high-pressure outer cylinder (2-1), the high-pressure balance drum steam seal (2-5) is assembled at the adjusting end of the high-pressure outer cylinder (2-1), and the high-pressure moving blades and the high-pressure static blades are respectively assembled on the high-pressure rotor (2-6) and the high-pressure inner cylinder (2-2).

6. The double reheat steam turbine and the matched double heat recovery system of claim 1, wherein: the medium-pressure module (3) comprises a medium-pressure outer cylinder (3-1), a medium-pressure inner cylinder (3-2), two medium-pressure steam exhaust side end steam seals (3-3), a medium-pressure rotor (3-4), medium-pressure positive direction moving blades and medium-pressure positive direction stationary blades;

the middle-pressure inner cylinder (3-2) is arranged inside the middle-pressure outer cylinder (3-1), the middle-pressure rotor (3-4) is arranged in the horizontal center inside the middle-pressure inner cylinder (3-2), the middle-pressure rotor (3-4) is concentrically arranged with the ultrahigh-pressure rotor (1-6) and the high-pressure rotor (2-6), one middle-pressure steam-exhaust side steam seal (3-3) is arranged at the adjusting end of the middle-pressure outer cylinder (3-1), the other middle-pressure steam-exhaust side steam seal (3-3) is arranged at the electric end of the middle-pressure outer cylinder (3-1), and middle-pressure positive-direction moving blades and middle-pressure positive-direction static blades are respectively assembled on the middle-pressure rotor (3-4) and the middle-pressure inner cylinder (3-2).

7. The double reheat steam turbine and the matched double heat recovery system of claim 1, wherein: the first low-voltage module (4) and the second low-voltage module (5) have the same structure;

the first low-pressure module (4) comprises a low-pressure outer cylinder (4-1), a low-pressure inner cylinder (4-2), two low-pressure steam exhaust side end steam seals (4-3), two end corrugated sections (4-4), a low-pressure rotor (4-5), low-pressure square moving blades, low-pressure square static blades and a partition plate sleeve;

the low-pressure inner cylinder (4-2) is arranged inside the low-pressure outer cylinder (4-1), the low-pressure rotor (4-5) is arranged inside the low-pressure inner cylinder (4-2), a low-pressure steam exhaust side end steam seal (4-3) and an end corrugated joint (4-4) are sequentially arranged at the adjusting end of the low-pressure outer cylinder (4-1), the other end corrugated joint (4-4) and the low-pressure steam exhaust side end steam seal (4-3) are sequentially arranged at the electric end of the low-pressure outer cylinder (4-1), and the low-pressure square moving blades and the low-pressure square static blades are respectively assembled on the low-pressure rotor (4-5), the low-pressure inner cylinder and the partition plate sleeve.

8. The double reheat steam turbine and the associated double heat recovery system of claim 1 or 7, wherein: it also comprises a middle and low pressure communicating pipe (16),

the middle and low pressure communicating pipe (16) is arranged right above the middle pressure module (3), the fourth bearing box (9), the first low pressure module (4), the fifth bearing box (10) and the second low pressure module (5);

the middle and low pressure communicating pipe (16) comprises a first connecting pipe (16-1), a second connecting pipe (16-2), a third connecting pipe (16-3), a fourth connecting pipe (16-4) and a straight pipe (16-5);

the first connecting pipe (16-1), the second connecting pipe (16-2), the third connecting pipe (16-3), the fourth connecting pipe (16-4) and the straight pipe (16-5) are integrated;

the first connecting pipe (16-1), the second connecting pipe (16-2), the third connecting pipe (16-3) and the fourth connecting pipe (16-4) are all arranged below the straight pipe (16-5), the first connecting pipe (16-1) is connected with the adjusting end of the medium-pressure outer cylinder (3-1) and communicated with the adjusting end of the medium-pressure outer cylinder, the second connecting pipe (16-2) is connected with the electric end of the medium-pressure outer cylinder (3-1) and communicated with the electric end of the medium-pressure outer cylinder, the third connecting pipe (16-3) is connected with the middle of the low-pressure outer cylinder (4-1) and communicated with the low-pressure outer cylinder, and the fourth connecting pipe (16-4) is connected with the middle of the low-pressure outer cylinder of the second low-pressure module (5) and communicated with the low-pressure outer cylinder.

9. The double reheat steam turbine and the matched double heat recovery system of claim 1, wherein: the steam turbine further comprises a thrust bearing which,

the thrust bearing is arranged on the second bearing box (7), and the absolute dead points are respectively positioned at the intersection points of the transverse positioning key and the longitudinal positioning key at the middle part of the first low-pressure module (4), the middle part of the second low-pressure module (5) and the bottom of the third bearing box (8).

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