Safety adjusting device for low-pressure cylinder of extraction condensing steam turbine

Abstract

The invention relates to the technical field of steam turbines, in particular to a safety adjusting device for a low-pressure cylinder of an extraction condensing steam turbine, which comprises a main body module comprising a steam turbine main body, a first steam supply unit and a control unit; the adjusting module comprises a first steam extraction unit, a second steam extraction unit, a third steam extraction unit, a fourth steam extraction unit, a second steam supply unit, a low-pressure steam conveying unit and a recovery unit, and can maintain the pressure of a six-stage steam extraction outlet, maintain the positive pressure state of six-stage steam extraction, reduce the possibility of forming a negative expansion difference and avoid the situation that the exhaust steam temperature is too high; the influence on the stability of the turbine low-pressure cylinder blade is avoided, and serious accidents such as turbine main body blade damage or failure, differential expansion out-of-control, bearing bush damage and dynamic and static collision and abrasion are effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbines, in particular to a safety adjustment device for a low-pressure cylinder of an extraction-condensing steam turbine. Background Art

[0002] At present, it has been found that the first three gear shaft seals of the six-extraction connection of the steam turbine in the heating unit have a six-extraction pressure close to 0 after the industrial steam extraction volume exceeds 200 tons / hour, and there is a possibility of shaft seal steam backflow. It is speculated that the excessive industrial steam extraction volume leads to insufficient steam flow in the rear cylinder, which makes the six-extraction unable to maintain positive pressure, resulting in a large heating load of the heating unit, and prone to problems such as high exhaust temperature of the low-pressure cylinder of the steam turbine, which in turn restricts the heating capacity, technical output and economy of the unit. In severe cases, it will affect the stability of the low-pressure cylinder blades, causing blade overheating, and even causing blade damage or failure, and malicious accidents such as differential expansion out of control, bearing damage, and dynamic and static friction. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention is proposed.

[0004] Therefore, an object of the present invention is to provide a safety adjustment device for a low-pressure cylinder of a condensing steam turbine.

[0005] To solve the above technical problems, the present invention provides the following technical solutions: including a main module, including a steam turbine main body, a first steam supply unit and a control unit; an adjustment module, including a first steam extraction unit, a second steam extraction unit, a third steam extraction unit, a fourth steam extraction unit, a second steam supply unit, a low-pressure steam transmission unit and a recovery unit.

[0006] As a preferred solution of the safety adjustment device of the low-pressure cylinder of the extraction-condensing steam turbine of the present invention, the first steam supply unit includes a turbine-boiler isolation door, a main steam inlet electric door, a first steam pipe and thermal instruments, the first steam pipe is connected to the turbine-boiler isolation door and the main steam inlet electric door, and the thermal instruments are arranged on the first steam pipe.

[0007] As a preferred solution of the safety adjustment device for the low-pressure cylinder of a condensing steam turbine of the present invention, the control unit includes a main steam valve, a second steam pipe, an A regulating valve and a B regulating valve, the second steam pipe is connected to the main steam valve, the A regulating valve and the B regulating valve, and the A regulating valve and the B regulating valve are both connected to the turbine body.

[0008] As a preferred solution of the safety adjustment device of the low-pressure cylinder of the extraction-condensing steam turbine of the present invention, wherein: the first extraction unit includes a first-stage extraction, a first extraction pipe, a second-stage extraction, a second extraction pipe and a third extraction pipe, the first-stage extraction and the second-stage extraction are both connected to the turbine body, the first extraction pipe is connected to the first-stage extraction, the second extraction pipe is connected to the second-stage extraction, and the third extraction pipe is connected to the second extraction pipe.

[0009] As a preferred solution of the safety adjustment device of the low-pressure cylinder of the extraction-condensing steam turbine of the present invention, the second extraction unit includes a three-stage extraction, a fourth extraction pipe, a front four-gear shaft seal and a third steam transmission pipe, the three-stage extraction is connected to the turbine body and the fourth extraction pipe, the front four-gear shaft seal is connected to the turbine body, the front four-gear extraction is connected to the third steam transmission pipe, and the third steam transmission pipe is connected to the fourth extraction pipe.

[0010] As a preferred solution of the safety adjustment device of the low-pressure cylinder of the extraction-condensing steam turbine of the present invention, the third extraction unit includes a fourth-stage extraction, a fifth extraction pipe, a fifth-stage extraction and a sixth extraction pipe, the fourth-stage extraction and the fifth-stage extraction are both connected to the turbine body, the fifth extraction pipe is connected to the fourth-stage extraction, and the sixth extraction pipe is connected to the fifth-stage extraction.

[0011] As a preferred solution of the safety adjustment device of the low-pressure cylinder of the extraction-condensing steam turbine of the present invention, wherein: the fourth extraction unit includes a six-stage extraction, a seventh extraction pipe, a first three-gear shaft seal and a fourth steam supply pipe, the six-stage extraction and the first three-gear shaft seal are connected to the turbine body, the seventh extraction pipe is connected to the six-stage extraction, the fourth steam supply pipe is connected to the first three-gear shaft seal and the seventh extraction pipe, and the first three-gear shaft seal is connected to the first four-gear shaft seal.

[0012] As a preferred solution of the safety adjustment device of the low-pressure cylinder of the extraction condensing steam turbine of the present invention, wherein: the second steam supply unit includes a deaerator steam balance pipe, a steam seal pressure regulating valve, a first steam supply pipe, a second steam supply pipe, a third steam supply pipe, a front two gear shaft seal and a rear two gear shaft seal, the steam seal pressure regulating valve is connected with the deaerator steam balance pipe and the first steam supply pipe, the second steam supply pipe and the third steam supply pipe are both connected with the first steam supply pipe, the second steam supply pipe and the third steam supply pipe are respectively connected with the front two gear shaft seal and the rear two gear shaft seal, the front two gear shaft seal and the rear two gear shaft seal are connected with the steam turbine body, and the front two gear shaft seal is connected with the front three gear shaft seal.

[0013] As a preferred solution of the safety adjustment device of the low-pressure cylinder of the extraction condensing steam turbine of the present invention, the low-pressure steam delivery unit includes a first delivery pipe, a front gear shaft seal, a rear gear shaft seal, a second delivery pipe, a third delivery pipe, a fourth delivery pipe, a steam extraction valve stem leakage pipe and a steam seal heater, the front gear shaft seal and the rear gear shaft seal are connected to the steam turbine body, the second delivery pipe is connected to the first gear shaft seal and the rear gear shaft seal, the second delivery pipe and the first delivery pipe are both connected to the third delivery pipe, the steam extraction valve stem leakage pipe is connected to the third delivery pipe, the third delivery pipe is connected to the steam seal heater, the front gear shaft seal is connected to the front two gear shaft seals, and the rear gear shaft seal is connected to the rear two gear shaft seals.

[0014] As a preferred solution of the safety adjustment device of the low-pressure cylinder of the extraction condensing steam turbine of the present invention, the recovery unit includes the first five gear shaft seals, the shaft seal steam transmission pipe, the main steam valve rod leakage pipe, the regulating valve rod leakage pipe and the fifth steam transmission pipe, the first five gear shaft seals are connected with the first four gear shaft seals, the shaft seal steam leakage pipe is connected with the first five gear shaft seals, the main steam valve rod leakage pipe is connected with the regulating valve rod leakage pipe, and the shaft seal leakage pipe and the main steam valve rod leakage pipe are both connected with the fifth steam transmission pipe.

[0015] The beneficial effects of the safety adjustment device for the low-pressure cylinder of a condensing steam turbine of the present invention are as follows: by adjusting the flow rate from the third-stage extraction to the #1 low-pressure heater and the flow rate from the fifth-stage extraction to the #2 low-pressure heater, the outlet pressure of the sixth-stage extraction is maintained, the positive pressure state of the sixth-stage extraction is maintained, the possibility of forming a negative expansion difference is reduced, and the exhaust steam temperature is prevented from being too high, the stability of the low-pressure cylinder blades of the turbine is prevented, and the occurrence of serious accidents such as damage or failure of the main blades of the turbine, loss of control of differential expansion, damage to the bearing, dynamic and static friction, etc., thereby solving the problems existing in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is an overall schematic diagram of the safety adjustment device for the low-pressure cylinder of a condensing steam turbine.

[0018] Figure 2 This is a partial structural schematic diagram of the safety adjustment device for the low-pressure cylinder of a condensing steam turbine.

[0019] Figure 3 This is an overall schematic diagram of the safety adjustment device for the low-pressure cylinder of a condensing steam turbine.

[0020] Figure 4 This is a partial structural schematic diagram of the safety adjustment device for the low-pressure cylinder of a condensing steam turbine.

[0021] Figure 5 This is a partial structural schematic diagram of the adjustment module of the safety adjustment device for the low-pressure cylinder of a condensing steam turbine.

[0022] Figure 6 This is a data diagram of the safety adjustment device for the low-pressure cylinder of a condensing steam turbine.

[0023] In the figure: 100, main module; 101, steam turbine main body; 102, first steam supply unit; 102a, boiler isolation door; 102b, main steam inlet electric door; 102c, first steam pipe; 102d, thermal instrument; 102e, pipeline; 103, control unit; 103a, main steam valve; 103b, second steam pipe; 103c, A regulating valve; 103d, B regulating valve; 200, adjustment module; 201, first steam extraction unit; 2 01a, first stage steam extraction; 201b, first steam extraction pipe; 201c, second stage steam extraction; 201d, second steam extraction pipe; 201e, third steam extraction pipe; 202, second steam extraction unit; 202a, third stage steam extraction; 202b, fourth steam extraction pipe; 202c, first four gear shaft seal; 202d, third steam transmission pipe; 203, third steam extraction unit; 203a, fourth stage steam extraction; 203b, fifth steam extraction pipe; 203c, fifth stage steam extraction; 203d, sixth steam extraction Steam pipe; 204, fourth steam extraction unit; 204a, sixth stage steam extraction; 204b, seventh steam extraction pipe; 204c, first three gear shaft seal; 204d, fourth steam transmission pipe; 205, second steam supply unit; 205a, deaerator steam balance pipe; 205b, steam seal pressure regulating valve; 205c, first steam supply pipe; 205d, second steam supply pipe; 205e, third steam supply pipe; 205f, first two gear shaft seal; 205g, rear two gear shaft seal; 206, low gas Compressed steam delivery unit; 206a, first delivery pipe; 206b, front gear shaft seal; 206c, rear gear shaft seal; 206d, second delivery pipe; 206e, third delivery pipe; 206f, extraction valve stem air leakage pipe; 206g, steam seal heater; 207, recovery unit; 207a, front five gear shaft seals; 207b, shaft seal steam delivery pipe; 207c, main steam valve stem air leakage pipe; 207d, regulating valve stem air leakage pipe; 207e, fifth steam delivery pipe. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0027] Example 1

[0028] Reference Figure 1 to Figure 5 , which is the first embodiment of the present invention, and this embodiment provides a safety adjustment device for the low-pressure cylinder of a condensing steam turbine, which includes a main module 100, including a turbine main body 101, a first steam supply unit 102 and a control unit 103; an adjustment module 200, including a first extraction unit 201, a second extraction unit 202, a third extraction unit 203, a fourth extraction unit 204, a second steam supply unit 205, a low-pressure steam delivery unit 206 and a recovery unit 207.

[0029] Furthermore, the first steam supply unit 102 includes a boiler isolation door 102a, a main steam inlet electric door 102b, a first steam pipe 102c, a thermal instrument 102d and a pipeline 102e, the first steam pipe 102c is connected to the boiler isolation door 102a and the main steam inlet electric door 102b, and the thermal instrument 102d is arranged on the first steam pipe 102c; the control unit 103 includes a main steam valve 103a, a second steam pipe 103b, an A regulating valve 103c and a B regulating valve 103d, the second steam pipe 103b is connected to the main steam valve 103a, the A regulating valve 103c and the B regulating valve 103d, and the A regulating valve 103c and the B regulating valve 103d are both connected to the turbine body 101.

[0030] The first steam pipe 102c is connected with the boiler isolation door 102a and the main steam inlet electric door 102b. The boiler isolation door 102a is connected with the boiler. The boiler burns and heats water to become high-temperature and high-pressure steam, which enters the first steam pipe 102c through the boiler isolation door 102a. The boiler is a prior art and will not be described in detail here. The thermal instrument 102d is used to measure the steam flow. The pipeline 102e is connected with the main steam valve 103a and the main steam inlet electric door 102b. The main steam valve 103a is quickly closed by it under abnormal conditions. To close the steam inlet of the steam turbine to ensure safe shutdown (it should be noted that: during the startup of the steam turbine body 101, the automatic main steam valve 103a is responsible for controlling the rate at which steam flows into the steam turbine to ensure that the steam turbine can smoothly accelerate to a predetermined speed. During the startup of the steam turbine body 101, the automatic main steam valve 103a adjusts the flow of main steam according to the change of the unit speed to maintain the stable control speed of the steam turbine body 101. At the same time, in an emergency, the automatic main steam valve 103a can be quickly closed to cut off the steam turbine body 101. The A regulating valve 103c and the B regulating valve 103d control the steam inlet amount of the steam turbine. It is also possible to fine-tune the opening to control the steam inlet pressure when the load is stable. In an emergency, the A regulating valve 103c and the B regulating valve 103d are closed by the protection command like the automatic main steam valve 103a (it should be noted that the A regulating valve 103c and the B regulating valve 103d accurately control the steam flow entering the high-pressure cylinder in the steam turbine body 101 by adjusting the opening to meet the steam turbine body 101 under different working conditions. The power demand is met, and the high-pressure cylinder steam inlet pressure is maintained within an appropriate range through adjustment to ensure efficient and stable operation of the steam turbine body 101. During the startup of the steam turbine body 101, the A regulating valve 103c and the B regulating valve 103d work together with the automatic main steam valve 103a to gradually increase the steam flow until the steam turbine reaches the rated speed. At the same time, in the event of an abnormal situation, the A regulating valve 103c and the B regulating valve 103d can respond quickly to reduce or cut off the steam supply, thereby protecting the steam turbine body 101).

[0031] Preferably, the first steam extraction unit 201 includes a first-stage steam extraction 201a, a first steam extraction pipe 201b, a second-stage steam extraction 201c, a second steam extraction pipe 201d and a third steam extraction pipe 201e, the first-stage steam extraction 201a and the second-stage steam extraction 201c are both connected to the steam turbine body 101, the first steam extraction pipe 201b is connected to the first-stage steam extraction 201a, the second steam extraction pipe 201d is connected to the second-stage steam extraction 201c, and the third steam extraction pipe 201e is connected to the second steam extraction pipe 201d; the second steam extraction unit 202 includes a third-stage steam extraction 202a, a fourth steam extraction pipe 202b, a front four-gear shaft seal 202c and a third steam transmission pipe 202d, the third-stage steam extraction 202a is connected to the steam turbine body 101 and the fourth steam extraction pipe 202b, the front four-gear shaft seal 202 c is connected to the turbine body 101, the first four gear extraction is connected to the third steam pipe 202d, and the third steam pipe 202d is connected to the fourth extraction pipe 202b; the third extraction unit 203 includes a fourth extraction 203a, a fifth extraction pipe 203b, a fifth extraction 203c and a sixth extraction pipe 203d, the fourth extraction 203a and the fifth extraction 203c are both connected to the turbine body 101, the fifth extraction pipe 203b is connected to the fourth extraction 203a, and the sixth extraction pipe 203d is connected to the fifth extraction 203c; the fourth extraction unit 204 includes a sixth extraction 204a, a seventh extraction pipe 204b, a first three gear shaft seal 204c and a fourth steam pipe 204d, and the sixth extraction 204a and the first three gear shaft seal 204c are connected to the turbine body 101. The first steam supply pipe 205a is connected to the main body 101, the seventh steam extraction pipe 204b is connected to the sixth-stage steam extraction pipe 204a, the fourth steam transmission pipe 204d is connected to the front three gear shaft seal 204c and the seventh steam extraction pipe 204b, and the front three gear shaft seal 204c is connected to the front four gear shaft seal 202c; the second steam supply unit 205 includes a deaerator steam balance pipe 205a, a steam seal pressure regulating valve 205b, a first steam supply pipe 205c, a second steam supply pipe 205d, a third steam supply pipe 205e, a front two gear shaft seal 205f and a rear two gear shaft seal 205g, the steam seal pressure regulating valve 205b is connected to the deaerator steam balance pipe 205a and the first steam supply pipe 205c, the second steam supply pipe 205d and the third steam supply pipe 205e are both connected to the first steam supply pipe 205c, and the second steam supply pipe 205c is connected to the first steam supply pipe 205c. 5d and the third steam supply pipe 205e are respectively connected with the front two gear shaft seal 205f and the rear two gear shaft seal 205g, the front two gear shaft seal 205f and the rear two gear shaft seal 205g are connected with the turbine body 101, and the front two gear shaft seal 205f is connected with the front three gear shaft seal 204c; the recovery unit 207 includes the front five gear shaft seal 207a, the shaft seal steam pipe 207b, the main steam valve rod leakage pipe 207c, the regulating valve rod leakage pipe 207d and the fifth steam pipe 207e, the front five gear shaft seal is connected with the front four gear shaft seal 202c, the shaft seal steam leakage pipe is connected with the front five gear shaft seal, the main steam valve rod leakage pipe 207c is connected with the regulating valve rod leakage pipe 207d, and the shaft seal leakage pipe and the main steam valve rod leakage pipe 207c are both connected with the fifth steam pipe 207e.

[0032] It should be noted that the boiler burns and heats water to become high-temperature and high-pressure steam that enters the steam turbine, releasing energy to rotate the blades in the steam turbine body 101. The energy of each blade decreases (pressure and temperature decrease) after each circle. At different pressure and temperature stages, a portion of steam is extracted through the first-stage extraction 201a, the second-stage extraction 201c, the third-stage extraction 202a, the fourth-stage extraction 203a, the fifth-stage extraction 203c and the sixth-stage extraction 204a for use. The third-stage extraction 202 a. The fifth-stage extraction steam 203c and the sixth-stage extraction steam 204a heat the condensate in the condenser (condensed by the steam of the entire turbine), the first gear shaft seal, the second gear shaft seal 205f, the second gear shaft seal 205g, the third gear shaft seal 204c, the fourth gear shaft seal 202c and the fifth gear shaft seal 207a are all used to seal the turbine bearings to prevent air from entering the turbine and also to prevent steam from leaking directly into the air. The fifth gear shaft seal 207a itself leaks.

[0033] When in use, steam enters the steam turbine through the boiler isolation door 102a, the first steam pipe 102c, the main steam inlet electric door 102b, the pipeline 102e, the main steam valve 103a, the second steam pipe 103b, the A regulating valve 103c and the B regulating valve 103d, so that the blades in the steam turbine body 101 rotate, and part of the steam is sent to the condenser. The first-stage steam extraction 201a transmits part of the steam to the #1 high-pressure heating water through the first steam extraction pipe 201b (after preheating, it enters the boiler to be formally heated and turned into steam), and the second-stage steam extraction 201c transmits part of the steam through the third steam extraction pipe 201b. The third stage steam extraction 202a transmits part of the steam to the #1 low temperature heater through the fourth steam extraction pipe 202b to heat the water condensed by the exhaust steam at the end of the steam turbine body 101, the fourth stage steam extraction 203a transmits part of the steam to the bubbling deoxygenation device through the fifth steam extraction pipe 203b to heat the condensed water for separating the dissolved oxygen in the water, and the fifth stage steam extraction 203c transmits part of the steam to the sixth steam extraction pipe 203c through the sixth steam extraction pipe 203d to heat the condensed water. 03d is transported to the exhaust steam condensed at the end of the #2 low-temperature heating steam turbine body 101. The sixth-stage extraction 204a transports part of the steam to the exhaust steam condensed at the end of the #3 low-temperature heating steam turbine body 101 through the seventh extraction pipe 204b. The first five-speed shaft seal 207a is the steam leakage of the steam turbine body 101 itself, and the pressure is very high. Part of it is transported to the deaerator for heating (heating other things but not being heated) through the shaft seal steam pipe 207b and the fifth steam pipe 207e, and part of it flows to the first four-speed shaft seal. The steam in the first four-speed shaft seal 202c is partly transported through the third steam pipe 202c. The steam in the first three gear shaft seal 204c is partially transported to the seventh steam extraction pipe 204b through the fourth steam transmission pipe 204d and transported to the #3 low-temperature heater for heating and heat recovery. The steam leaked from the main steam valve 103a, the A regulating valve 103c and the B regulating valve 103d is transported to the deaerator for heating through the main steam valve stem leakage pipe 207c, the regulating valve stem leakage pipe 207d and the fifth steam transmission pipe 207e.

[0034] The deaerator steam balance pipe 205a supplies steam, so that the steam is transported to the front second gear shaft seal 205f and the rear second gear shaft seal 205g through the steam seal pressure regulating valve 205b, the first steam supply pipe 205c, the second steam supply pipe 205d and the third steam supply pipe 205e. The steam seal steam supply pressure is maintained by means of the steam seal pressure regulating valve 205b, and the steam temperature is about 120°C to ensure that the main steam is sealed and does not leak, cool the front shaft neck of the steam turbine body 101, and ensure the normal operation of the bearing of the steam turbine body 101. When starting, the rotor and cylinder of the steam turbine body 101 are preheated; when shutting down, the front steam seal of the rotor of the steam turbine body 101 is heated to prevent the negative expansion difference from exceeding the limit;

[0035] The greater the amount of steam supplied by the second-stage extraction 201c, the less steam goes to the back of the turbine, and the positive pressure at the sixth-stage extraction 204a changes to negative pressure. At this time, the sixth-stage extraction 204a will produce a back suction phenomenon, resulting in the inhalation of higher temperature steam delivered from the front three-gear shaft seal 204c, which increases the cylinder temperature at the sixth-stage extraction 204a. The temperature of the sixth-stage extraction 204a suddenly becomes higher than the ambient temperature, causing it to expand more, exceeding the expansion degree of the rotor in this area, forming a negative expansion difference. Therefore, it is necessary to reduce the flow rate by closing the isolation gates (valves) at the third-stage extraction 202a and the fifth-stage extraction 203c, so that the sixth-stage extraction 204a can return to positive pressure, thereby maintaining the positive pressure state of the sixth-stage extraction 204a.

[0036] In summary, by adjusting the flow rate from the third-stage extraction steam 202a to the #1 low-pressure heater and the flow rate from the fifth-stage extraction steam 203c to the #2 low-pressure heater, the outlet pressure of the sixth-stage extraction steam 204a is maintained, the possibility of forming a negative expansion difference is reduced, and the exhaust steam temperature is avoided from being too high, the stability of the low-pressure cylinder blades of the turbine is avoided, and the damage or failure of the blades of the turbine body 101, the loss of control of differential expansion, the damage to the bearing, the dynamic and static friction and other serious accidents are avoided.

[0037] Example 2

[0038] Reference Figure 3 to Figure 5, which is the second embodiment of the present invention. Different from the previous embodiment, this embodiment provides a safety adjustment device for a low-pressure cylinder of an extraction condensing steam turbine, which includes a low-pressure steam delivery unit 206 including a first delivery pipe 206a, a front gear shaft seal 206b, a rear gear shaft seal 206c, a second delivery pipe 206d, a third delivery pipe 206e, a fourth delivery pipe, an extraction valve stem leakage pipe 206f and a steam seal heater 206g, a front gear shaft seal 206b and a rear gear shaft seal 206c. 06c is connected to the turbine body 101, the second delivery pipe 206d is connected to the first gear shaft seal and the rear gear shaft seal 206c, the second delivery pipe 206d and the first delivery pipe 206a are both connected to the third delivery pipe 206e, the extraction valve stem leakage pipe 206f is connected to the third delivery pipe 206e, the third delivery pipe 206e is connected to the steam seal heater 206g, the front gear shaft seal is connected to the front two gear shaft seals 205f, and the rear gear shaft seal is connected to the rear two gear shaft seals 205g.

[0039] When in use, the low-pressure steam leaked from the steam valve, the front gear shaft seal and the rear gear shaft seal is transported to the third delivery pipe 206e through the first delivery pipe 206a and the second delivery pipe 206d, and then transported to the steam seal heater 206g through the third delivery pipe 206e. The low-pressure steam in the steam extraction valve stem leakage pipe 206f is transported to the steam seal heater 206g through the third delivery pipe 206e, so as to recover the leaked low-pressure steam to heat the condensate.

[0040] Example 3

[0041] Reference Figure 6 , which is the third embodiment of the present invention. Different from the previous embodiment, this embodiment provides a safety adjustment device for the low-pressure cylinder of a condensing steam turbine, which includes adjusting the three-stage extraction 202a of the unit to the #1 low-pressure steam inlet valve and the five-stage extraction 203c to the #2 low-pressure steam inlet valve, the low-pressure steam inlet temperature is significantly reduced, the steam flow layout of the low-pressure cylinder is effectively improved, the difference in the expansion value between the rotor and the cylinder is reduced, and the differential expansion is restored to normal. At the same time, the steam seal blowby is reduced, the shaft seal steam leakage is improved, and the unit vacuum is maintained normal. Through data comparison and actual adjustment, it is found that when the #3 low-pressure water level is maintained at about 700mm, the low-pressure steam inlet temperature is stably maintained at a relatively low value (68°C). At this time, the operating condition of the low-pressure cylinder has better safety, which is suitable for reference by the same type of low-capacity thermal power units.

[0042] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0043] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0044] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0045] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A safety adjustment device for a low-pressure cylinder of an extraction-condensing steam turbine, characterized in that: include, A main body module (100) includes a steam turbine main body (101), a first steam supply unit (102) and a control unit (103); An adjustment module (200) comprises a first steam extraction unit (201), a second steam extraction unit (202), a third steam extraction unit (203), a fourth steam extraction unit (204), a second steam supply unit (205), a low-pressure steam delivery unit (206) and a recovery unit (207); The first steam supply unit (102) is connected to the control unit (103) and the steam turbine body (101). The steam supplied by the boiler is transported to the control unit (103) through the first steam supply unit (102), and then transported to the steam turbine body (101) through the control unit (103). The first steam extraction unit (201), the second steam extraction unit (202), the third steam extraction unit (203), and the fourth steam extraction unit (204) are all connected to the steam turbine body (101). The first steam extraction unit (201), the second steam extraction unit (202), the third steam extraction unit (203) and the fourth steam extraction unit (204) extract the steam supplied to the steam turbine body (101) at different stages. The low-pressure steam delivery unit (206) and the recovery unit (207) are both connected to the control unit (103). The low-pressure steam delivery unit (206) delivers the leaked low-pressure steam to heat condensate, and the recovery unit (207) recovers the leaked steam to the deoxidizer.

2. The safety adjustment device for low-pressure cylinder of extraction-condensing steam turbine according to claim 1, characterized in that: The first steam supply unit (102) comprises a turbine and boiler isolation door (102a), a main steam inlet electric door (102b), a first steam transmission pipe (102c) and a thermal instrument (102d); the first steam transmission pipe (102c) is connected to the turbine and boiler isolation door (102a) and the main steam inlet electric door (102b); and the thermal instrument (102d) is arranged on the first steam transmission pipe (102c).

3. The safety adjustment device for low-pressure cylinder of extraction-condensing steam turbine according to claim 2, characterized in that: The control unit (103) comprises a main steam valve (103a), a second steam transmission pipe (103b), an A regulating valve (103c) and a B regulating valve (103d); the second steam transmission pipe (103b) is in communication with the main steam valve (103a), the A regulating valve (103c) and the B regulating valve (103d); and the A regulating valve (103c) and the B regulating valve (103d) are both in communication with the steam turbine body (101).

4. The safety adjustment device for the low-pressure cylinder of an extraction-condensing steam turbine according to claim 3, characterized in that: The first steam extraction unit (201) comprises a first-stage steam extraction (201a), a first steam extraction pipe (201b), a second-stage steam extraction (201c), a second steam extraction pipe (201d) and a third steam extraction pipe (201e); the first-stage steam extraction (201a) and the second-stage steam extraction (201c) are both connected to the steam turbine body (101); the first steam extraction pipe (201b) is connected to the first-stage steam extraction (201a); the second steam extraction pipe (201d) is connected to the second-stage steam extraction (201c); and the third steam extraction pipe (201e) is connected to the second steam extraction pipe (201d).

5. The safety adjustment device for low-pressure cylinder of extraction-condensing steam turbine according to claim 4, characterized in that: The second steam extraction unit (202) comprises a third-stage steam extraction (202a), a fourth steam extraction pipe (202b), a front four-speed shaft seal (202c) and a third steam transmission pipe (202d); the third-stage steam extraction (202a) is connected to the steam turbine body (101) and the fourth steam extraction pipe (202b); the front four-speed shaft seal (202c) is connected to the steam turbine body (101); the front four-speed steam extraction is connected to the third steam transmission pipe (202d); and the third steam transmission pipe (202d) is connected to the fourth steam extraction pipe (202b).

6. The safety adjustment device for the low-pressure cylinder of an extraction-condensing steam turbine according to claim 5, characterized in that: The third steam extraction unit (203) comprises a fourth-stage steam extraction (203a), a fifth steam extraction pipe (203b), a fifth-stage steam extraction (203c) and a sixth steam extraction pipe (203d); the fourth-stage steam extraction (203a) and the fifth-stage steam extraction (203c) are both connected to the steam turbine body (101); the fifth steam extraction pipe (203b) is connected to the fourth-stage steam extraction (203a); and the sixth steam extraction pipe (203d) is connected to the fifth-stage steam extraction (203c).

7. The safety adjustment device for the low-pressure cylinder of an extraction-condensing steam turbine according to claim 6, characterized in that: The fourth steam extraction unit (204) comprises a sixth-stage steam extraction (204a), a seventh steam extraction pipe (204b), a front three-gear shaft seal (204c) and a fourth steam transmission pipe (204d); the sixth-stage steam extraction (204a) and the front three-gear shaft seal (204c) are in communication with the steam turbine body (101); the seventh steam extraction pipe (204b) is in communication with the sixth-stage steam extraction (204a); the fourth steam transmission pipe (204d) is in communication with the front three-gear shaft seal (204c) and the seventh steam extraction pipe (204b); and the front three-gear shaft seal (204c) is in communication with the front four-gear shaft seal (202c).

8. The safety adjustment device for the low-pressure cylinder of an extraction-condensing steam turbine according to claim 7, characterized in that: The second steam supply unit (205) comprises a deaerator steam balance pipe (205a), a steam seal pressure regulating valve (205b), a first steam supply pipe (205c), a second steam supply pipe (205d), a third steam supply pipe (205e), a front second gear shaft seal (205f) and a rear second gear shaft seal (205g); the steam seal pressure regulating valve (205b) is connected to the deaerator steam balance pipe (205a) and the first steam supply pipe (205c); the second steam supply pipe The first steam supply pipe (205d) and the third steam supply pipe (205e) are both connected to the first steam supply pipe (205c), the second steam supply pipe (205d) and the third steam supply pipe (205e) are respectively connected to the front second gear shaft seal (205f) and the rear second gear shaft seal (205g), the front second gear shaft seal (205f) and the rear second gear shaft seal (205g) are connected to the turbine body (101), and the front second gear shaft seal (205f) is connected to the front third gear shaft seal (204c).

9. The safety adjustment device for the low-pressure cylinder of an extraction-condensing steam turbine according to claim 8, characterized in that: The low-pressure steam delivery unit (206) comprises a first delivery pipe (206a), a front gear shaft seal (206b), a rear gear shaft seal (206c), a second delivery pipe (206d), a third delivery pipe (206e), a steam extraction valve stem leakage pipe (206f) and a steam seal heater (206g). The front gear shaft seal (206b) and the rear gear shaft seal (206c) are connected to the steam turbine body (101), and the second delivery pipe (206d) is connected to the third delivery pipe (206e). The first gear shaft seal is connected to the next gear shaft seal (206c), the second delivery pipe (206d) and the first delivery pipe (206a) are both connected to the third delivery pipe (206e), the steam extraction valve stem leakage pipe (206f) is connected to the third delivery pipe (206e), the third delivery pipe (206e) is connected to the steam seal heater (206g), the first gear shaft seal is connected to the first two gear shaft seals (205f), and the next gear shaft seal is connected to the next two gear shaft seals (205g).

10. The safety adjustment device for the low-pressure cylinder of an extraction-condensing steam turbine according to claim 9, characterized in that: The recovery unit (207) comprises a first five-gear shaft seal (207a), a shaft seal steam transmission pipe (207b), a main steam valve stem leakage pipe (207c), a regulating valve stem leakage pipe (207d) and a fifth steam transmission pipe (207e); the first five-gear shaft seal is connected to the first four-gear shaft seal (202c); the shaft seal steam leakage pipe is connected to the first five-gear shaft seal; the main steam valve stem leakage pipe (207c) is connected to the regulating valve stem leakage pipe (207d); and the shaft seal leakage pipe and the main steam valve stem leakage pipe (207c) are both connected to the fifth steam transmission pipe (207e).

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