JPH045900Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field to which the invention pertains) The present invention relates to a drain pipe water seal structure of a gland steam condenser of a steam turbine.

(Prior art and its problems) A labyrinth packing is provided at the location where the turbine axle of a steam turbine passes through the casing (shaft seal) to prevent internal steam from leaking to the outside.
In addition, when the inside of a low-pressure turbine is a vacuum, ground steam is introduced from the middle of the labyrinth packing to prevent air from entering. In either case, simply providing a labyrinth packing cannot completely prevent steam from leaking into the atmosphere, so the steam flowing through the labyrinth packing and the ground steam are guided to the gland steam condenser, and the labyrinth packing is removed from the labyrinth packing. The negative pressure is maintained at several mmAg lower than atmospheric pressure to prevent steam leakage.

FIG. 2 is a block diagram of a conventional gland steam condenser of this type. 1 is a grand steam condenser;
A cooling water pipe 2 through which cooling water as a cooling medium flows is disposed within the condenser 1 . A grand steam line 3 equipped with a stop valve 4 for guiding ground steam is connected to the upper part of the grand steam condenser 1, and the ground steam line 3 is branched from the upstream side of the stop valve 4 to form an intermediate line. A water seal tube 5 is provided, which has an S-shaped trap 5a (hereinafter referred to as water seal portion 5a) at its end, and whose terminal end is open to the atmosphere. The water seal pipe 5 is for maintaining the airtightness of the grand steam condenser 1. Therefore, a certain amount of water is retained in the water seal part 5a to balance the internal pressure of the condenser 1, and to maintain the airtightness of the gland steam condenser 1. It is designed to prevent backflow of water.
Furthermore, in the water seal pipe 5, the cooling water pipe 2 arranged in the grand steam condenser 1 is damaged, and a large amount of cooling water leaks, overflows the inside of the condenser 1, and overflows into the grand steam pipe 3. When this occurs, the water is discharged to the outside via the water seal pipe 5, thereby preventing the water from flowing back to the steam turbine side. To maintain the accumulated water head in the water seal section 5a, a water supply pipe 6 equipped with a stop valve 7 is disposed on the open side of the section 5a, and is configured to replenish the accumulated water.

The grand steam condenser 1 also includes a drain pipe 8 which has the role of balancing the internal pressure and atmospheric pressure of the condenser, maintaining airtightness, and appropriately discharging condensate stored inside the condenser to the outside. A drain trap 8 is installed in a part of the ground steam condenser 1 so that one end is connected to the bottom of the ground steam condenser 1 and the other end is opened to the atmosphere.
It is arranged with a. A part of the discharged condensate stays in this drain trap 8a, thereby maintaining airtightness and pressure balance.

Gland steam supplied to the shaft seal of the steam turbine is recovered to the gland steam condenser 1 via the gland steam line 3, where it is cooled in contact with the cooling water pipe 2, condensed, and condensed. Water becomes water and is stored at the bottom of the condenser 1, and a predetermined amount or more is discharged to the outside via the drain pipe 8. Therefore, the inside of the grand steam condenser 1 is maintained at a negative pressure slightly lower than atmospheric pressure. There is. Therefore, in order to maintain such a state, the water seal portion 5a of the water seal pipe 5 and the drain trap 8a of the drain pipe 8 must be able to retain a certain amount of water at all times and discharge excess water to the outside. It is necessary to keep it in a possible state.

However, in the grand steam condenser 1, which is equipped with a water-sealed tube structured as described above, there is a risk that the sealed water may freeze in winter and not function smoothly. In addition to heating the water seal portion 5a, a water supply pipe 6 is arranged to replenish the shortage of accumulated water. Therefore, the water seal tube 5 has the disadvantage that it must be equipped with a heating tube and also have a water supply means.

(Purpose of the invention) The present invention was created in view of the above points, and provides an economical grand steam condenser in which the water seal pipe does not require anti-freezing means or water replenishment means. The purpose is to provide.

(Summary of the invention) According to the invention, the above object is to connect the open end of a drain pipe without a drain trap to the lower part of the S-shaped trap for water sealing of a water sealing pipe, and to communicate the drain pipe and the water sealing pipe. This can be achieved by allowing the condensate of the gland steam condenser to flow through the water seal S-shaped trap.

(Embodiment of the invention) An embodiment of the invention will be described below based on the drawings. FIG. 1 is a block diagram of a gland steam condenser according to an embodiment of the present invention. In FIG. 1, the drain pipe 8 is made in a shape without a curved pipe part that is a drain trap, and together with the water seal pipe 5 described in detail in the explanation section of the prior art, the drain pipe 8 is used to maintain the airtightness of the gland steam condenser 1. It is designed to allow for smooth water drainage.

That is, the drain pipe 8, which connects one end to the bottom of the grand steam condenser 1 and extends downward, is bent at a right angle at a predetermined position, and its open end is connected to the S-shape of the water seal portion 5a of the water seal pipe 5. The drain pipe 8 and the water seal portion 5a form a communicating pipe. As a result, the gland steam that has flowed down through the shaft seal of the steam turbine (not shown) is recovered to the gland steam condenser 1 via the gland steam pipe line 3, and the cooling water pipe installed in the condenser 1. 2, it is cooled and condensed into condensate, which is stored at the bottom of the condenser 1. A predetermined amount or more flows down the drain pipe 8 and further into the water seal section 5.
It will be discharged to the outside through a. Therefore, the condensate that is overflowing water is used as water sealing water for the water sealing pipe section 5a.

(Effect of the invention) As is clear from the above explanation, according to the invention, the open end of the drain pipe of the gland steam condenser is connected below the water seal part of the water seal pipe, and the condensate is transferred to the drain pipe. Since the water is discharged to the outside via the water seal section, the overflowing condensate water is used as water seal water, so the water seal section of the water seal pipe is warmed by the condensate and the water seal water is heated. Replenishment will also be carried out at all times, except during turbine downtime. Therefore, there is no need for warm pipe equipment or water supply means as seen in conventional devices, and the manufacturing cost can be reduced accordingly, and the drain pipe can be manufactured easily.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a gland steam condenser according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional gland steam condenser. DESCRIPTION OF SYMBOLS 1...Gland steam condenser, 3...Ground steam pipe line, 5...Water seal pipe, 5a...Water seal portion, 8...
...Drain pipe, 8a...Drain trap.

Claims (1)

[Scope of utility model registration request] A water seal pipe is branched from the ground steam pipe line connecting the shaft seal part of the steam turbine and the ground steam condenser, and has an S-shaped water seal trap in the middle part and an open end. In a gland steam condenser equipped with a drain pipe having a drain trap and an open end, the drain trap of the drain pipe is eliminated, and the open end of the drain pipe is connected below the S-shaped trap for water sealing, and the drain pipe is connected to the drain pipe. A gland steam condenser characterized in that a pipe and the water seal pipe are connected to each other so that condensate of the gland steam condenser flows through the water seal pipe S-shaped trap.