JP2001349204A - Turbine gland leakage steam recovering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent steam from being mixed in lubricating oil when flowing out of gland parts by recovering gland leakage steam when causing power failure in plant operation in a turbine gland leakage steam recovering device. SOLUTION: At ordinary operation time of a turbine, the steam is supplied to the gland parts G1 to G6, clearance between a turbine rotor and a casing is sealed, the leakage steam after sealing flows in a gland steam condenser 8 by passing through a direct contact heat exchanger 20 from a leak line 7, and is cooled by cold water introduced from a condensate pump 10, and is recovered as drain. When causing the power failure in turbine operation, the condensate pump 10 and an exhaust fan 9 stop, the leakage steam cannot be recovered, the steam flows out of the gland parts, a control device 26 opens opening-closing valves 22 and 24, and controls so as to drive a pump 25 and the exhaust fan 9 by an emergency power source 27, pure water is made to flow to the direct contact heat exchanger 20, the steam is contacted with water, and is recovered as the drain.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recovering steam leaked from a turbine gland, and has a structure for recovering steam leaked from a turbine gland even when a power failure occurs during operation of a turbine plant. This is to prevent the occurrence of such a problem that steam is mixed into the bearing oil.

[0002]

2. Description of the Related Art In a steam turbine plant, steam is usually supplied to a gland in order to prevent steam from flowing out of the turbine from a turbine gland or to prevent air from flowing in from the outside of the turbine. These defects are prevented by flowing steam to seal the gland.

FIG. 4 is a system diagram of ground steam of a conventional steam turbine. In the figure, the steam from the main steam passes through the primary pressure reducing valve 5 to the feed line 4, and the steam from the auxiliary steam source passes through the feed line 4 and passes through the secondary pressure reducing devices 6 a, 6 b, 6 c, 6 d, respectively. The pressure is reduced and supplied to the ground parts G1, G2, G3, G4, G5, G6. G
Reference numerals 1 and G2 denote ground portions at both ends of the rotor of the high-pressure turbine 1, G3 and G4 denote ground portions at both ends of the rotor of the low-pressure turbine 2, and G5 and G6 denote ground portions at both ends of the rotating shaft of the feed water pump driving turbine 3. The ground steam supplied to each of the gland portions G1 to G6 is supplied as steam having a higher pressure than the inside of the turbine, and prevents the steam from flowing from the inside of the turbine to the outside through the gap between the casing and the shaft. Air is prevented from flowing into the inside from outside through this gap. The steam after the sealing of the gland steam is collected from the gland through the leak line 7, and is collected by the gland steam condenser 8
To be collected. In the ground steam condenser 8, cold water is guided from a condenser (not shown) by a condensate pump 10, and the collected ground steam is condensed and collected as drain.
The air that has flowed in with the steam is discharged to the atmosphere by the exhaust fan 9.

FIG. 5 is a structural view of the above-described gland portion. Since the rotor 41 of the turbine 42 rotates, both ends of the casing 40 have a gap, and this portion has a ring shape in the axial direction. The three packings 43 are arranged close to the rotor 41 and are fixed to the casing 42 to form the ground part 50. Here, the sealing steam chambers 60 a and 60 b are formed by the packing 43, and sealing steam is supplied to the inner sealing steam chamber 60 a through a ground steam supply pipe 61. This sealing steam has a pressure (1.3 at.) Higher than the atmospheric pressure (1.033 at.).
a) The steam is regulated to a degree, and the outer sealing steam chamber 60b has a pressure slightly lower than the atmosphere (0.98 at
), And the gland steam leaking from the seal steam chamber 60a side is collected through the gland steam discharge pipe 62 together with the air flowing in from the rotor end.

In the conventional ground steam system having the above structure, if power is lost during plant operation and a power failure occurs, the exhaust fan 9 and the condensing pump 10 shown in FIG. The recovery function of the turbine is lost, and the steam leaked from the turbine glands G1 to G6 cannot be collected, leaks and flows out from the gland, and the leaked steam gets into the bearings and mixes with the bearing oil to damage the bearings. Troubles occur.

[0006]

As described above, in the conventional ground steam system, when a power failure occurs during plant operation, an exhaust fan or a condensate pump of a ground steam condenser for recovering the steam leaked from the ground. Stops, and the gland steam condenser stops functioning. As a result, the steam leaking from the gland part leaks out of the gland part without being collected and gets into the bearing part and is mixed into the bearing oil. Of course, this may cause an abnormality in the lubricating oil system.

Accordingly, the present invention adds a function of recovering steam leaked from the ground portion even when a power failure occurs during plant operation, and this function is immediately activated at the time of a power failure to leak from the ground portion. An object of the present invention is to provide a turbine gland leakage steam recovery device capable of recovering steam.

[0008]

The present invention provides the following means (1) and (2) to solve the above-mentioned problems.

(1) Turbine for supplying steam to a turbine gland to seal the gland, guiding the leaked steam after sealing to a gland steam condenser having an exhaust fan through a leak line, condensing and collecting it as drain. In the ground leak steam recovery device, a direct contact heat exchanger provided in the middle of the leak line and guiding the leaked steam to the ground steam condenser, and a water supply pump and an on-off valve, wherein water is supplied to the direct contact heat exchanger. A water supply line for supplying water and steam in direct contact with each other, and a drain discharge line having an on-off valve for discharging drain from the direct contact heat exchanger,
An emergency power supply for supplying power to the water supply pump and the exhaust fan at the time of a power failure, and closing and opening of the water supply line on-off valve and the drain discharge line during normal operation of the turbine, and opening and closing the two on-off valves at the time of a power failure. A control device for controlling the emergency power supply to supply power to the feed water pump and the exhaust fan.

(2) a bypass line that bypasses the direct heat exchanger and flows steam directly from the leak line to the gland steam condenser, an on-off valve provided in the bypass line, and the direct heat exchange An on-off valve for opening and closing steam flowing into the heat exchanger, and the control device opens and closes the on-off valve of the bypass line and closes the on-off valve of the direct contact heat exchanger during normal operation of the turbine. The on-off valve of the water supply line and the on-off valve of the drain discharge line are closed. In the event of a power failure, the on-off valve of the bypass line is closed, the on-off valve of the direct contact heat exchanger is opened, and the on-off valve and the drain of the water supply line are further opened. 2. The tar control according to claim 1, further comprising: opening an on-off valve of a discharge line, and activating the emergency power supply to supply power to the water supply pump and the exhaust fan. Down ground leakage vapor recovery system.

In (1) of the present invention, when a power failure occurs during operation of the turbine plant, the condensate pump and the exhaust fan of the gland steam condenser are stopped, and the leaked steam after sealing the gland portion is recovered. Function is lost,
The steam leaks out of the gland and strikes the bearings,
It is mixed in bearing oil. When a power failure occurs, the control device opens the on-off valve of the water supply line and the on-off valve of the drain discharge line, and simultaneously controls the water supply pump and the exhaust fan to connect to an emergency power supply. With such control, water flows from the water supply line into the direct heat exchanger, and the leaked steam flowing into the direct heat exchanger comes into direct contact with the water, whereby the steam is cooled and drained, and the drain discharge line Recovered from. Therefore, even if a power failure occurs, the leaked steam from the gland after sealing is continuously collected, and does not flow out of the gland and enter the bearing oil.

In (2) of the present invention, during normal operation, the control device controls the on-off valve so as to collect the sealed steam leaking from the gland through the bypass line into the gland steam condenser, At the time of power failure, this bypass line is closed to guide the leaked steam to the direct contact heat exchanger, and water is introduced from the water supply line so that each open / close valve is brought into direct contact with the steam and water in the direct contact heat exchanger. It is controlled to discharge as drain from the drain discharge line. Other controls are the same as those of the invention of the above (1).
In the same manner as in the invention, even in the event of a power failure, it is possible to prevent a problem that steam enters the bearing oil without leaking steam from the gland.

[0013]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a configuration diagram of a turbine gland leakage steam recovery device according to a first embodiment of the present invention. In the figure, reference numerals 1 to 10 have the same functions as those of the conventional example shown in FIG. 3, and the same reference numerals are used as they are, and detailed description is omitted, but characteristic portions of the present invention are indicated by reference numerals 20 to 27. These features will be described in detail below.

In FIG. 1, reference numeral 20 denotes a direct contact heat exchanger having a structure shown in FIG. 3 described later, which guides the steam leaked from the ground to make direct contact with water to make the steam drain. 21 is a pure water supply line, 22 is an on-off valve, 23 is a drain discharge line, and 24 is an on-off valve for discharging drain. 25 supplies pure water with a pump. Reference numeral 26 denotes a control device, which receives a power supply system signal S and opens the on-off valves 22 and 24 when a power failure is detected.
Control is performed to output a signal for driving the pump 25.
Reference numeral 27 denotes an emergency power supply for supplying power to the pump 25 and the exhaust fan 9 during a power failure.

In the turbine gland steam recovery system having the above-described structure, during normal operation, gland leaking steam passes through the leak line 7, passes through the direct contact heat exchanger, and is led to the gland steam condenser 8, where it is drained as in the prior art. Will be collected as When a power failure occurs during plant operation, the control device 26
Detects the power failure because the power supply system signal S is input. In a power outage state, the condensing pump 10 and the exhaust fan 9 stop, and it becomes impossible to collect the leaked steam from the ground, and the steam leaks from the glands G1 to G6 to the outside, flows out, enters the bearing portion, mixes with oil, and has a problem. Occurs, the control device 26
Outputs a signal for activating the emergency power supply 27 upon detecting a power failure, and drives the emergency power supply 27 to supply power to the pump 25 from the emergency power supply 27 to drive the pump.
24 is opened.

In this state, pure water is supplied to the pure water supply line 21 by the pump 25, and the pure water flows into the direct contact heat exchanger 20. On the other hand, the ground leakage steam is
0, the steam comes into direct contact with the water, and the steam is cooled by the water to form a drain, and the drain discharge line 2
Recovered from 3. When the power failure recovers, the condensate pump 10
And the exhaust fan 9 are driven, the control device 26 outputs a signal to stop the emergency power supply 27 to stop the supply of power to the pump 25 and the exhaust fan 9,
2, 24 are closed to return the plant to normal operation.

In the first embodiment described above,
A pure water supply system including a small-capacity pump 25, on-off valves 22, 24 and a direct contact heat exchanger 20 is provided. During normal operation, gland leaking steam is passed from the leak line 7 through the direct contact heat exchanger 20. It is led to the ground steam condenser 8 and collected as drain. When a power failure occurs during plant operation, pure water is supplied from the pure water supply system into the direct contact heat exchanger 20, and the steam and water are brought into direct contact with each other in the direct contact heat exchanger 20 to collect the steam as a drain. Therefore, even if a power failure occurs, the leakage of the ground leakage from the ground parts G1 to G6 is prevented from flowing out.

Although the supply to the direct contact heat exchanger 20 has been described with reference to pure water, it is not always necessary to use pure water, and the same effect can be obtained with ordinary water. is there. The emergency power source 27 is a small capacity water supply pump 25.
And only the exhaust fan 9 is driven, and a small-sized diesel generator may be provided, and the large-capacity ground steam condensate pump 10 and the like are not driven. With such a configuration, it is possible to prevent the leakage of ground leakage steam to the outside at the time of a power failure. Although the water supply pump 25 has been described as being installed, if water is supplied from a water source installed at a high place such as a head tank, there is no problem even if the water supply pump 25 is not installed.

FIG. 2 is a configuration diagram of a turbine gland leakage steam recovery device according to a second embodiment of the present invention. The feature of the second embodiment is that a system through which the recovered steam from the leak line 7 passes through the direct contact heat exchanger 20 and the direct contact heat exchanger 20
Are provided, and the system is switched by an on-off valve during normal operation and during a power failure.

FIG. 2 is different from FIG. 1 in the configuration provided with on-off valves 30, 31 and line 32, and the other configuration is the same as that of the first embodiment shown in FIG. The on-off valve 31 is a valve that opens and closes the flow path of the direct heat exchanger 20 from the leak line 7, and the on-off valve 30 is provided on the line 32.
This is for bypassing 0 and flowing to the ground steam condenser 8.

In the above-structured gland steam recovery apparatus, during normal operation, the control device 26 controls the on-off valves 22 and 2.
4, 31 are closed, the on-off valve 30 is opened, and the emergency power supply 27 is controlled so as not to operate. In this state, the ground leaking steam passes from the leak line 7 to the line 32,
It flows into the ground steam condenser 8. In the condenser 8, cold water is guided from a condenser (not shown) by a condenser pump 10, and the inflowing steam is condensed by the cold water and collected as a drain.

When a power failure occurs during plant operation,
The control device 26 detects the power failure by the signal S, and
Is closed, the on-off valves 22, 24 and 31 are opened, and the emergency power supply 27 is operated to supply power to the pump 25 and the exhaust fan 9. In this state, the steam leaked from the leak line 7 through the gland passes through the on-off valve 31 and passes through the direct heat exchanger 20.
Flows into. On the other hand, pure water is supplied to the direct contact heat exchanger 20 through the pure water supply line 21 by the pump 25, and the steam and water come into direct contact with each other, and the steam is cooled and drained. Is discharged to

According to the second embodiment described above, the small capacity pump 25, the on-off valves 22, 24 and the direct heat exchanger 2
0, and a line 32 for bypassing the direct contact heat exchanger 20 is provided, so that a power failure occurs during plant operation as in the first embodiment. Even if it occurs, the ground leakage steam
Outflow from 1 to G6 to the outside is prevented. In addition, the emergency generator 27 does not drive the large-capacity condensate pump 10 or the like, but only needs to supply power to the small-capacity pump 25 and the exhaust fan 9. In addition, it is possible to prevent the leakage of the ground leakage steam to the outside during a power failure.

FIG. 3 is a side view of the direct contact heat exchanger used in the first and second embodiments described above. The direct contact heat exchanger 20 has a cooling water inlet 40 connected to a line 21, Spray device 41 for spraying cooling water, air vent nozzle 4
2. It is composed of a ground leaking steam injection nozzle 43 and a draining nozzle 44 connected to the leak line 7.

In the direct contact heat exchanger 20 having the above-described structure, the steam is guided from the leak line 7 to the ground leak steam injection nozzle 43. The nozzle 43 is formed of a perforated tube and jets steam into the container. The cooling water inlet 4 passes through the line 21 from above.
Cooling water (pure water) is supplied from 0 to the upper water chamber, and is sprayed into the container through the spray nozzle 41, so that the water is brought into direct contact with the ground leaking steam rising from the lower part of the heat exchanger, so that the steam is discharged. Let it condense. The sprinkled cooling water and steam condensed water are discharged from a drain nozzle 44 at the bottom of the container. The air that flows in together with the gland leaking steam and the non-condensable gas generated by steam condensation are discharged from the air vent nozzle 42 at the top of the container.

[0026]

According to the present invention, there is provided a turbine gland leakage steam recovery apparatus comprising: (1) supplying steam to a turbine gland portion to seal the gland portion, and transmitting the leaked steam after sealing through a leak line to a gland steam recovery device provided with an exhaust fan; In a turbine gland leak steam recovery device that guides the steam to a condenser and collects the collected steam as a drain, a direct contact heat exchanger that is provided in the middle of the leak line and guides the leaked steam to the ground steam condenser, a feedwater pump, and A drain supply line comprising an on-off valve for supplying water to the direct contact heat exchanger and bringing water and steam into direct contact, and a drain discharge having an on-off valve for discharging drain from the direct contact heat exchanger A line, an emergency power supply for supplying power to the water supply pump and the exhaust fan in the event of a power failure, and an on-off valve for the water supply line during normal operation of the turbine. A control device that closes the on-off valve of the drain discharge line, opens both on-off valves in the event of a power failure, and controls the emergency power supply to supply power to the water supply pump and the exhaust fan. It is characterized by.

With this configuration, when a power failure occurs, the control device opens the on-off valve of the water supply line and the on-off valve of the drain discharge line, and at the same time controls the water supply pump and the exhaust fan to connect to the emergency power supply. With such control, water flows from the water supply line into the direct heat exchanger, and the leaked steam flowing into the direct heat exchanger comes into direct contact with the water, whereby the steam is cooled and drained, and the drain discharge line Recovered from. Therefore, even if a power failure occurs, the leaked steam from the gland after sealing is continuously collected, and does not flow out of the gland and enter the bearing oil.

According to (2) of the present invention, in the invention of (1), the bypass line, an on-off valve provided on the bypass line, and an on-off valve for opening and closing steam flowing into the direct contact heat exchanger. During normal operation, the control device controls the on-off valve to collect the sealed steam leaking from the gland through the bypass line to the gland steam condenser during normal operation. While closing this bypass line and guiding the leaked steam to the direct contact heat exchanger, each open / close valve is controlled so that water is introduced from the water supply line and the steam and water are brought into direct contact in the direct contact heat exchanger, Drain is discharged from the drain discharge line. Other controls are the same as those of the invention of the above (1).
In the same manner as in the invention, even in the event of a power failure, it is possible to prevent a problem that steam enters the bearing oil without leaking steam from the gland.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a turbine gland leakage steam recovery device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a turbine gland leakage steam recovery device according to a second embodiment of the present invention.

FIG. 3 is a side view of a direct contact heat exchanger used in the first and second embodiments of the present invention.

FIG. 4 is a configuration diagram of a conventional turbine gland leaking steam recovery device.

FIG. 5 is a general sectional view showing a ground portion of a turbine.

[Explanation of symbols]

 Reference Signs List 1 high-pressure turbine 2 low-pressure turbine 3 feedwater pump driving turbine 4 feed line 7 leak line 8 ground steam condenser 9 exhaust fan 10 condensate pump 20 direct contact heat exchanger 21 pure water supply line 22, 24, 30, 31 opening and closing Valve 23 Drain discharge line 25 Pump 26 Controller 27 Emergency power supply 32 Line

Claims (2)

[Claims] 1. A turbine gland for supplying steam to a turbine gland portion to seal the gland portion, guiding the leaked steam after sealing to a gland steam condenser having an exhaust fan through a leak line, condensing and collecting as a drain. In the leaked steam recovery device, a direct contact heat exchanger is provided in the middle of the leak line and guides the leaked steam to the ground steam condenser, and a water supply pump and an on-off valve are provided to supply water to the direct contact heat exchanger. A water supply line for directly contacting water and steam, a drain discharge line having an on-off valve for discharging the drain from the direct contact heat exchanger, and an electric power supply to the feed pump and the exhaust fan during a power outage. The power supply for emergency supply and the on / off valve of the water supply line and the on / off valve of the drain discharge line are closed during normal operation of the turbine. A turbine gland leakage steam recovery device, comprising: a control device that opens a valve and controls the emergency power supply to operate so as to supply power to the feedwater pump and the exhaust fan. 2. A bypass line that bypasses the direct contact heat exchanger and flows steam directly from the leak line to the gland steam condenser, an on-off valve provided in the bypass line, and the direct contact heat exchanger. An on-off valve for opening and closing steam flowing into the turbine, the control device opens the on-off valve of the bypass line and closes the on-off valve of the direct contact heat exchanger during normal operation of the turbine, The on-off valve of the supply line and the on-off valve of the drain discharge line are closed. At the time of a power failure, the on-off valve of the bypass line is closed, the on-off valve of the direct contact heat exchanger is opened, and the on-off valve and the drain discharge of the water supply line are further opened. 2. The turbine system according to claim 1, wherein the on-off valve of the line is opened, and the emergency power supply is operated to supply power to the water supply pump and the exhaust fan. Land leak steam recovery device.