CN210268275U

CN210268275U - Vacuum lifting system suitable for cutting off low-pressure cylinder operation of steam turbine

Info

Publication number: CN210268275U
Application number: CN201920060127.0U
Authority: CN
Inventors: 赵奚可
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-01-15
Filing date: 2019-01-15
Publication date: 2020-04-07
Anticipated expiration: 2029-01-15

Abstract

The utility model discloses a be suitable for vacuum lift system of steam turbine excision low pressure cylinder operation, be suitable for vacuum lift system of steam turbine excision low pressure cylinder operation includes: a condenser having a first mixed media inlet, a drain, and a hot well communication port; a first vapor jet pump having a first motive medium inlet, a first suction medium inlet, and a first mixed medium outlet; the first suction medium inlet is suitable for being connected with an evacuation pipe of a condenser, and the first mixed medium outlet is connected with the first mixed medium inlet. According to the utility model discloses be suitable for vacuum lift system of steam turbine excision low pressure cylinder operation has stable performance, receives operating mode and environmental factor to influence advantage such as little.

Description

Vacuum lifting system suitable for cutting off low-pressure cylinder operation of steam turbine

Technical Field

The utility model relates to a combined heat and power generation technical field particularly, relates to a be suitable for vacuum lift system of steam turbine excision low pressure cylinder operation.

Background

Under the high vacuum state, the steam-free operation technology of the low pressure cylinder of the steam turbine is an effective means for realizing thermoelectric decoupling in the heat supply period, can fully improve the peak shaving flexibility of the thermal power generating unit, and meets the requirement of a power grid on load scheduling.

In the related art, the water ring vacuum pump is mainly used for vacuumizing equipment of a condensing steam turbine generator set, and the performance of the water ring vacuum pump is unstable and is greatly influenced by working conditions and environmental factors.

For example, under the operating condition that the unit cuts off the low-pressure cylinder, the heat load of the condenser is less, and the operating condition that the low-pressure cylinder is cut off at the same time is winter, the temperature of circulating cooling water is lower, and the unit is theoretically in a low back pressure (high vacuum) operating state, but is influenced by the limit suction pressure of the water ring vacuum pump (the limit vacuum of the water ring vacuum pump is 3.3kPa), the problem of air accumulation may occur in a vacuum system of the steam turbine, so that the blast friction risk is increased, and the damage is caused to last stages of blades of the steam turbine. In addition, when the condenser works under normal back pressure, the suction capacity of the condenser is sharply reduced along with the reduction of the inlet pressure of the vacuum pump due to the suction characteristic of the water ring vacuum pump. In addition, in summer, along with the increase of temperature, the cavitation of the water ring vacuum pump is increased, the performance is rapidly reduced, the vacuum of the condenser is poor, and the economic efficiency of the unit is reduced.

Disclosure of Invention

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, an object of the utility model is to provide a be suitable for the vacuum lift system of steam turbine excision low pressure cylinder operation, this vacuum lift system that is suitable for steam turbine excision low pressure cylinder operation has stable performance, receives operating mode and environmental factor to influence advantage such as little.

According to the utility model discloses an embodiment provides a be suitable for vacuum lift system of steam turbine excision low pressure cylinder operation, the vacuum lift system who is suitable for steam turbine excision low pressure cylinder operation includes: a condenser having a first mixed media inlet, a drain, and a hot well communication port; a first vapor jet pump having a first motive medium inlet, a first suction medium inlet, and a first mixed medium outlet; the first suction medium inlet is suitable for being connected with an evacuation pipe of a condenser, and the first mixed medium outlet is connected with the first mixed medium inlet.

According to the utility model discloses be suitable for vacuum lift system of steam turbine excision low pressure cylinder operation has stable performance, receives operating mode and environmental factor to influence advantage such as little.

According to some embodiments of the utility model, be suitable for the vacuum lift system of steam turbine excision low pressure cylinder operation still includes: a second vapor jet pump having a second motive medium inlet, a second suction medium inlet, and a second mixed medium outlet; the condenser is also provided with a middle extraction port and a second mixed medium inlet, the second suction medium inlet is connected with the middle extraction port, and the second mixed medium outlet is connected with the second mixed medium inlet.

Further, a first sub-bin and a second sub-bin are defined in the condenser; the first mixed medium inlet and the middle extraction port are communicated with the first sub-bin, the second mixed medium inlet and the emptying port are communicated with the second sub-bin, and the number of the hot well communication ports is at least two, wherein the hot well communication ports are respectively communicated with the first sub-bin and the second sub-bin.

Further, the first motive medium inlet and the second motive medium inlet are connected in parallel to a motive medium manifold.

Further, the motive medium manifold is adapted to be connected to a main steam discharge of the boiler.

According to some specific examples of the present invention, each of the first and second steam jet pumps comprises: a pump housing having a motive medium end, a suction medium end, a mixed medium end, and an ejection chamber in communication with the suction medium end and the mixed medium end, respectively, the suction medium end disposed adjacent to the motive medium end; and the power nozzle is arranged at the power medium end of the pump shell and is communicated with the jet chamber.

Further, the ejection chamber includes a head portion, a mixing portion, and a diffusion portion, which are sequentially communicated in a direction from the motive medium end to the mixed medium end; wherein the motive nozzle and the suction media end communicate with the head, the mixing media end communicates with the diffuser portion, the mixing portion decreases in diameter in a direction from the head to the diffuser portion, and the diffuser portion increases in diameter in a direction from the mixing portion away from the mixing portion.

According to some embodiments of the invention, the condenser has a condenser pipe, the condenser pipe is adapted to be connected in parallel to the condenser pipe of the condenser.

Further, the cooling water pipe is located downstream of the condensate pump on the condensate pipe.

According to some embodiments of the utility model, be suitable for the vacuum lift system of steam turbine excision low pressure cylinder operation still includes: the vacuumizing equipment is provided with a water ring vacuum pump and is suitable for being connected with a vacuumizing pipe of the condenser; and the control device is used for controlling the input and the cut-off of the first steam jet pump and the vacuum pumping equipment.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic diagram of a vacuum lift system suitable for a steam turbine to cut off low pressure cylinder operation according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a first steam jet pump of a vacuum lift system adapted for turbine cut-off low pressure cylinder operation according to an embodiment of the present invention.

Fig. 3 is a graph comparing suction pressure to suction volume for a vacuum lift system, a water ring vacuum pump, and a roots pump suitable for turbine cut low pressure cylinder operation, in accordance with an embodiment of the present invention.

Reference numerals:

a vacuum lifting system 1 suitable for the operation of the steam turbine for cutting off the low pressure cylinder,

A condenser 100, a first mixed medium inlet 110, a drain 120, a hot well communication port 130, an intermediate extraction port 140, a second mixed medium inlet 150, a first sub-bin 160, a second sub-bin 170, a cooling water pipe 180,

A first steam jet pump 200, a first motive medium inlet 210, a first suction medium inlet 220, a first mixed medium outlet 230,

A second vapor jet pump 300, a second motive medium inlet 310, a second suction medium inlet 320, a second mixed medium outlet 330,

A power medium main pipe 400,

A pump housing 510, a motive medium end 511, a suction medium end 512, a mixed medium end 513, an ejection chamber 514, a motive nozzle 520, a head 5141, a mixing section 5142, a diffuser section 5143, a nozzle outlet, a nozzle inlet, a nozzle outlet, a,

A vacuum-pumping device 600,

A vacuum-pumping pipe 2,

Condensate pipe 3, condensate pump 31.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention. In addition, in the description of the present invention, "the first feature" and "the second feature" may include one or more of the features.

A vacuum lift system 1 suitable for a steam turbine to cut off low pressure cylinder operation according to an embodiment of the present invention is described below with reference to the accompanying drawings.

As shown in fig. 1 to 3, a vacuum lift system 1 for a steam turbine cutting low pressure cylinder operation according to an embodiment of the present invention includes a condenser 100 and a first steam jet pump 200.

The condenser 100 has a first mixed media inlet 110, a drain 120, and a thermal well communication port 130. The first steam jet pump 200 has a first motive medium inlet 210, a first suction medium inlet 220 and a first mixed medium outlet 230. The first suction medium inlet 220 is adapted to be connected to the evacuation tube 2 of the condenser, and the first mixed medium outlet 230 is connected to the first mixed medium inlet 110.

Fig. 3 shows a graph comparing the suction pressure and suction amount of the vacuum lift system 1 according to the embodiment of the present invention with those of the water ring vacuum pump and the roots pump in the related art.

As shown in fig. 3, when the vacuum degree of the condenser is close to the limit vacuum, the suction amount of the water ring vacuum pump is significantly reduced and the performance is attenuated compared with the suction amount of the vacuum lifting system 1 according to the embodiment of the present invention. And when the vacuum degree of the condenser is lower than the limit vacuum value, the suction amount of the first steam jet pump 200 is basically kept unchanged, and the performance is stable.

According to the utility model discloses be suitable for vacuum lift system 1 of steam turbine excision low pressure cylinder operation, the ultimate vacuum is high, and the extreme pressure of bleeding is low, can stabilize the suction under low pressure environment, reduces the operation backpressure of condenser, and it is very matchd with cutting jar technique, and the power consumption reduces simultaneously, maintains simply safe and reliable. According to the utility model discloses be suitable for vacuum lift system 1 of steam turbine excision low pressure cylinder operation to compare the water ring vacuum pump among the prior art, no longer influenced by ambient temperature, annual average unit improves about 0.2-0.5kPa in vacuum, effectively avoids the production of cavitation phenomenon, and does not have any rotation piece, and the power saving rate reaches 100%.

Therefore, according to the utility model discloses be suitable for vacuum lift system 1 of steam turbine excision low pressure cylinder operation has the stable performance, receives operating mode and environmental factor to influence advantage such as little.

In some embodiments of the present invention, as shown in fig. 1, the vacuum lift system 1 adapted for turbine cut-off low pressure cylinder operation further comprises a second steam jet pump 300.

The second vapor jet pump 300 has a second motive medium inlet 310, a second suction medium inlet 320, and a second mixed medium outlet 330.

The condenser 100 also has an intermediate extraction opening 140 and a second mixed-medium inlet 150, the second suction-medium inlet 320 being connected to the intermediate extraction opening 140, and the second mixed-medium outlet 330 being connected to the second mixed-medium inlet 150.

Further, the condenser 100 may be a shell and tube heat exchanger, and the condenser 100 defines therein a first sub-compartment 160 and a second sub-compartment 170. The first mixed medium inlet 110 and the intermediate extraction port 140 are communicated with the first sub-bin 160, the second mixed medium inlet 150 and the evacuation port 120 are communicated with the second sub-bin 170, and the number of the thermal well communication ports 130 is at least two, which are respectively communicated with the first sub-bin 160 and the second sub-bin 170, that is, the first sub-bin 160 has at least one thermal well communication port 130 and the second sub-bin 170 has at least one thermal well communication port 130.

Specifically, the exhaust steam of the first steam jet pump 200 enters the first sub-compartment 160 of the condenser 100 through the first mixed medium outlet 230 and the first mixed medium inlet 110 in order. The steam-water mixture after heat exchange in the first sub-bin 160 is extracted by a second steam injection pump 300 through the middle extraction port 140 and the second suction medium inlet 320 in sequence, steam is exhausted to the second sub-bin 170 of the condenser 100 through the second mixed medium outlet 330 and the second mixed medium inlet 150 in sequence, the non-condensed gas after heat exchange in the second sub-bin 170 is exhausted through the exhaust port 120, the condensed water is drained and returns to a hot well through the hot well communication port 130 for recovery

Alternatively, as shown in fig. 1, the first motive medium inlet 210 and the first motive medium inlet 210 are connected in parallel to a motive medium manifold 400, and the motive medium manifold 400 is adapted to be connected to a main steam discharge port of the boiler, and consumes only a small amount of energy of a low or medium level as a driving source.

In some embodiments of the present invention, as shown in fig. 2, each of the first and second

vapor jet pumps

200 and 300 includes a pump housing 510 and a power nozzle 520.

The pump housing 510 has a motive medium end 511, a suction medium end 512, a mixed medium end 513, and an ejection chamber 514. And an ejection chamber 514 communicating with the suction medium end 512 and the mixed medium end 513, respectively, the suction medium end 512 being disposed adjacent to the motive medium end 511. The motive nozzle 520 is disposed at the motive medium end 511 of the pump housing 510 and communicates with the ejection chamber 514. Taking the first vapor jet pump 200 as an example, the first motive medium inlet 210 is formed at the motive nozzle 520, the first suction medium inlet 220 is formed at the suction medium end 512, and the first mixed medium outlet 230 is formed at the first mixed medium outlet 230.

Further, the ejection chamber 514 includes a head portion 5141, a mixing portion 5142, and a diffusion portion 5143. The head portion 5141, the mixing portion 5142, and the diffuser portion 5143 are communicated in this order in the direction from the power medium end 511 to the mixed medium end 513.

Wherein the motive nozzle 520 and the suction medium end 512 are in communication with the head portion 5141, the mixing medium end 513 is in communication with the diffuser portion 5143, the diameter of the mixing portion 5142 is gradually reduced in a direction from the head portion 5141 to the diffuser portion 5143, and the diameter of the diffuser portion 5143 is gradually increased in a direction from the mixing portion 5142 to a distance from the mixing portion 5142.

Specifically, after steam enters the power nozzle 520 from the power medium end 511, supersonic jet flow is ejected from the power nozzle 520, vacuum is formed in the head 5141, the ejection entrains and accelerates the non-condensable gas sucked by the suction medium end 512 due to low suction pressure, the high-speed gas flow and the non-condensable gas enter the mixing portion 5142 to be mixed, the kinetic energy conversion pressure rises to a high level in the diffusion portion 5143, then the mixed gas enters the condenser 100 from the mixing medium end 513, the condensed steam is drained, the drained water returns to the hot well from the hot well communication port 130, and the non-condensable gas is discharged from the hot well communication port 130.

It will be appreciated by those skilled in the art that fig. 2 illustrates the first vapor jet pump 200 for ease of understanding, and the second vapor jet pump 300 may be configured with reference to the first vapor jet pump 200.

In some embodiments of the present invention, as shown in fig. 1, the condenser 100 has a cooling water pipe 180, and the cooling water pipe 180 is adapted to be connected in parallel to the condensate pipe 3 of the condenser, for example, the cooling water pipe 180 is located on the condensate pipe 3 downstream of the condensate pump 31. Therefore, the condensed water is used as a cooling water source of the condenser 100, the condensed water is intercepted from an outlet of the condensed water pump 31, the condensed water pipe 3 between the condensed water pipe and the condenser is added after heat exchange, and heat after heat exchange is returned to the condensed water system, so that the heat in the power steam and the exhaust steam of the condenser is completely recovered to the condensed water system, the economy is favorably improved, and the energy-saving effect is remarkable.

In some embodiments of the present invention, as shown in fig. 1, the vacuum lift system 1 suitable for the turbine to cut off the operation of the low pressure cylinder further includes a vacuum pumping device 600 and a control device.

The vacuum pumping device 600 has a water ring vacuum pump, and the vacuum pumping device 600 is adapted to be connected to the vacuum pumping tube 2 of the condenser. The control means is used to control the input and the cut-off of the first and second vapor jet pumps 200 and 300 and the vacuum evacuation apparatus 600. In other words, the control device may control the first vapor injection pump 200 and the second vapor injection pump 300 to participate in the operation, and may also control the vacuum pumping device 600 to participate in the operation, so as to adapt to different working conditions. For example, the first steam jet pump 200 and the second steam jet pump 300 can be switched on and off by a valve operated by a sequential control system in the DCS, and the operation is simple and reliable.

According to the utility model discloses be suitable for vacuum lift system 1 of steam turbine excision low pressure cylinder operation, the ultimate vacuum is 1.5kPa to possess the operational capability that maintains the ultimate vacuum, be suitable for the unit and remove the zero operating mode of exerting oneself of jar in winter, show and improve vacuum, reduce the coal consumption, equipment has only utilized the kinetic energy of power steam simultaneously, has carried out comprehensive recovery to heat energy, and the economic nature is showing. In addition, the first steam jet pump 200 and the second steam jet pump 300 are both static parts, so that the service power rate can be reduced, the power generation cost can be reduced, and the equipment does not have rotating parts and is more reliable in operation and maintenance.

Other constructions and operations of the vacuum lift system 1 adapted for operation of a steam turbine cut-off low pressure cylinder according to embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.

In the description herein, references to the description of the terms "particular embodiment," "particular example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A vacuum lift system adapted for turbine cut-off low pressure cylinder operation, comprising:

a condenser having a first mixed media inlet, a drain, and a hot well communication port;

a first vapor jet pump having a first motive medium inlet, a first suction medium inlet, and a first mixed medium outlet;

the first suction medium inlet is suitable for being connected with a vacuumizing pipe of a condenser, and the first mixed medium outlet is connected with the first mixed medium inlet;

the condenser is provided with a cooling water pipe, and the cooling water pipe is suitable for being connected in parallel with a condensation water pipe of the condenser.

2. The vacuum lift system for steam turbine cut-off low pressure cylinder operation of claim 1, further comprising:

a second vapor jet pump having a second motive medium inlet, a second suction medium inlet, and a second mixed medium outlet;

the condenser is also provided with a middle extraction port and a second mixed medium inlet, the second suction medium inlet is connected with the middle extraction port, and the second mixed medium outlet is connected with the second mixed medium inlet.

3. The vacuum lift system for steam turbine cut-off low pressure cylinder operation of claim 2, wherein said condenser defines a first sub-compartment and a second sub-compartment therein;

the first mixed medium inlet and the middle extraction port are communicated with the first sub-bin, the second mixed medium inlet and the emptying port are communicated with the second sub-bin, and the number of the hot well communication ports is at least two, wherein the hot well communication ports are respectively communicated with the first sub-bin and the second sub-bin.

4. The vacuum lift system for a steam turbine cutting low pressure cylinder operation of claim 3, wherein said first power medium inlet and said second power medium inlet are connected in parallel to a power medium manifold.

5. The vacuum lift system for steam turbine cut-off low pressure cylinder operation of claim 4, wherein said power medium manifold is adapted to be connected to a main steam discharge of a boiler.

6. The vacuum lift system adapted for steam turbine cut-off low pressure cylinder operation of claim 2, wherein each of said first steam jet pump and said second steam jet pump comprises:

a pump housing having a motive medium end, a suction medium end, a mixed medium end, and an ejection chamber in communication with the suction medium end and the mixed medium end, respectively, the suction medium end disposed adjacent to the motive medium end;

and the power nozzle is arranged at the power medium end of the pump shell and is communicated with the jet chamber.

7. The vacuum lift system for steam turbine cut-off low pressure cylinder operation according to claim 6, wherein said jet chamber comprises a head portion, a mixing portion and a diffuser portion, said head portion, said mixing portion and said diffuser portion being in sequential communication in a direction from said motive medium end to said mixed medium end;

wherein the motive nozzle and the suction media end communicate with the head, the mixing media end communicates with the diffuser portion, the mixing portion decreases in diameter in a direction from the head to the diffuser portion, and the diffuser portion increases in diameter in a direction from the mixing portion away from the mixing portion.

8. The vacuum lift system for steam turbine cut-off low pressure cylinder operation of claim 1, wherein said cooling water line is located downstream of a condensate pump on said condensate line.

9. The vacuum lift system for steam turbine cut-off low pressure cylinder operation of any one of claims 1 to 8, further comprising:

the vacuumizing equipment is provided with a water ring vacuum pump and is suitable for being connected with a vacuumizing pipe of the condenser;

and the control device is used for controlling the input and the cut-off of the first steam jet pump and the vacuum pumping equipment.