JP2650477B2 - Water hammer prevention method for deaerator water supply piping and piping equipment therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a condensate flowing through a downcomer connected to a deaerator and a boiler feed pump, particularly in a turbine facility including a boiler and a condensing turbine. A method for preventing the occurrence of water hammer at the junction when a part of the condensate flows into the condensate flowing into the condensate supply pipe for supplying double water to the deaerator and returning to the deaerator, and its piping equipment About.

[Conventional technology]

2. Description of the Related Art In a turbine facility including a boiler and a condensing turbine, there is known a water supply system shown in FIG. 2 as a water supply system for degassing condensed water from a condenser by a deaerator and supplying the dewatered water to a boiler.

In FIG. 2, a condensate supply pipe 1 includes a condensate pump 2, a flow control valve 3, an electric valve 4, a low-pressure heater 5, and a check valve 6, and is connected to a condenser 7 and a deaerator 8. The condensate supplied from the condenser 7 to the deaerator 8 flows. The downcomer 9 extends downward from the deaerator 8 and is connected to a boiler feed pump 10,
The condensed water degassed by the deaerator 8 is led to the boiler feed pump 10. Reference numeral 11 denotes a water supply pipe for supplying condensed water pressurized by the boiler water supply pump 10 to a boiler (not shown).

It is connected to the downcomer pipe 9 and the condensate supply pipe 1 downstream of the check valve 6, bypasses the deaerator 8, and includes a circulating pump 12, a check valve 13, and a deaerator bypass pipe 15 having an electric valve 14. A part of the deaerator bypass pipe 15, the deaerator 8, and the condensate supply pipe 1 and the downcomer 9 is used to return a part of the condensate flowing through the downcomer 9 to the deaerator. A water pipe 17 is formed.

The deaerator bypass piping 15 at the outlet of the circulation pump 12
And a warming water supply pipe 18 for supplying warm water for warming the boiler feed pump 10. Reference numeral 19 denotes a motor-operated valve.

With such a configuration, the condensate from the condenser 7 is pressurized by the condensate pump 2 in the condensate supply pipe 1 in the open state of the electric valve 4, the flow rate is controlled by the flow control valve 3, and the deaerator 8 Supplied to At this time, during operation of the turbine equipment, the condensed water is heated by the low-pressure heater 5 through which the extracted steam from the turbine flows, and then supplied to the deaerator 8, and heated and deaerated by the extracted steam supplied to the deaerator 8. When the turbine equipment is started, the condensed water is not heated by the low-pressure heater 5 but is supplied to the deaerator 8 at a low temperature without being extracted by the low-pressure heater 5 and communicates with the condenser 7 which is evacuated. The inside is evacuated and vacuum degassed. The degassed condensate flows down the downcomer 9 and is sent to the boiler feed pump 10, where the boiler feed pump
The water is pressurized by 10 and sent to the boiler via a water supply pipe 11.

By the way, in the start and stop of the turbine equipment frequently, for example, in the DSS (Daily Start Daily Stop) operation, the temperature of the condensed water in the deaerator 8 at the start of the turbine equipment is not much lower than that during the operation. . Therefore, when the turbine equipment is started, the high-temperature condensate in the deaerator 8 is circulated from the downcomer 9 through the deaerator 8 through the deaerator circulating water pipe 17 with the electric valve 14 opened by the circulation pump 12. Thereby, the temperature of the condensed water in the deaerator 8 and the condensed water in the downcomer 9 which are supplied through the condensate supply pipe 1 and supplied to the lower temperature condensate gas to lower the temperature are equalized. Avoid flash.

[Problems to be solved by the invention]

As described above, when the turbine equipment is started in the DSS operation, the condensate temperature in the deaerator 8 is a high temperature close to the temperature during operation. Therefore, when the turbine equipment is started and vacuum deaeration is started, the temperature of the condensate flowing from the deaerator 8 to the downcomer 9 and the deaerator bypass pipe 15 is higher than the condensate flowing through the condensate supply pipe 1, Furthermore, since the internal pressure of the condensate supply pipe 1 approaches the internal pressure of the deaerator 8 and enters the vacuum region, a franche is generated at the junction of the condensate supply pipe 1 and the deaerator bypass pipe 15, and this flash is generated. There was a problem that the air bubbles were crushed and water hammer was generated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for preventing water hammer in a deaerator water supply pipe, which can prevent the above-described water hammer when starting turbine equipment, and a pipe installation thereof.

[Means for solving the problem]

According to the present invention, according to the present invention, a condensate supply pipe that supplies condensate from a condenser to a deaerator by a condensate pump, and guides the degassed condensate in the deaerator to a boiler feed pump. Condenser and deaerator bypass piping that includes a precipitation pipe, a deaerator bypass pipe that bypasses the deaerator, and is connected to the condensate supply pipe and the precipitation pipe with a circulation pump, and that flows through the condensate supply pipe. In the method of preventing water hammer in the deaerator water supply pipe at the junction with the condensate flowing through the deaerator, part of the condensate supplied by the ascites pump flows through the deaerator bypass pipe. Shall be mixed. In addition, as a piping facility to prevent water hammer of the above-mentioned deaerator water supply pipe, it is connected to the condensate supply pipe at the outlet of the double water pump and the deaerator bypass pipe at the outlet of the circulation pump, and condenses water from the condenser. A water injection pipe that allows a part of the water to flow through shall be provided.

[Action]

When the turbine equipment starts up, part of the low-temperature condensate flowing through the condensate supply pipe to the high-temperature condensate inside the deaerator flowing through the deaerator bypass pipe and the condensate supply pipe at the outlet of the condensate pump and the circulation pump By feeding and mixing water by a condensate pump through a water injection pipe connected to the deaerator bypass pipe at the outlet, the temperature of the hot condensate flowing through the deaerator bypass pipe falls, The temperature drops to the saturation temperature corresponding to the internal pressure of the condensate flowing through the supply pipe. As a result, no flush occurs at the junction of the condensate flowing through the deaerator bypass pipe and the condensate flowing through the condensate supply pipe, and thus no water hammer occurs.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram of a deaerator water supply pipe provided with a water hammer prevention pipe facility according to an embodiment of the present invention. In FIG. 1, the same components as those in the conventional example of FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted. 1 is different from the conventional example in that the condensate supply pipe 1 at the outlet of the condensate pump 2 and the deaerator bypass pipe 15 downstream of the electric valve 14 as the outlet of the circulation pump 12 are connected. That is, a water injection pipe 21 having an air-operated piston valve 22 and a stop valve 23 is provided.

With such a configuration, when the turbine equipment is started, the condensate is sent from the condenser 7 by the condensate pump 2 to the deaerator 8 via the condensate supply pipe 1, while the high-temperature condensate in the deaerator 8 is conveyed. Is partially circulated through the deaerator circulating water pipe 17 by the circulation pump 12. At this time, the air-operated piston valve 22 and the stop valve 23 are opened to cool the low-temperature flowing through the condensate supply pipe 1 from the condenser 7. Part of the condensate is mixed with the high-temperature condensate flowing through the deaerator bypass pipe 15 via the water injection pipe 21 to lower the temperature, and the mixed condensate is reduced to the internal pressure of the condensate flowing through the condensate supply pipe 1. Lower to the corresponding saturation temperature. As a result, no flush occurs at the junction of the deaerator bypass pipe 15 and the condensate supply pipe 1, and accordingly, no water hammer occurs.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, when starting the turbine equipment, the high-temperature condensate flowing from the deaerator through the deaerator bypass pipe is mixed with the low-temperature condensate sent by the condensate pump. In addition, a water injection pipe is connected to the deaerator bypass pipe and the condensate supply pipe as piping equipment to perform this mixing, and the low-temperature condensate flowing through the condensate supply pipe is deaerated via the water injection pipe. By mixing with the hot condensate flowing through the pipe, the temperature of the hot condensate flowing through the deaerator bypass pipe decreases, and the temperature drops to the saturation temperature corresponding to the internal pressure of the condensate flowing through the condensate supply pipe. It is possible to prevent the occurrence of flush at the junction of the condenser bypass pipe and the condensate supply pipe, and to eliminate the water hammer accordingly.

[Brief description of the drawings]

FIG. 1 is a system diagram of a deaerator water supply pipe provided with a water hammer prevention piping system according to an embodiment of the present invention, and FIG. 2 is a system diagram of a conventional deaerator water supply pipe. 1: Condenser supply piping, 2: Condenser pump, 7: Condenser, 8: Deaerator,
9: Precipitator, 10: Boiler feed pump, 12: Circulation pump, 15:
Deaerator bypass piping, 21: water injection piping.

Claims (2)

(57) [Claims] 1. A condensate supply pipe for supplying condensate from a condenser to a deaerator by a condensate pump, a precipitation pipe for guiding the degassed condensate in the deaerator to a boiler feed pump, A deaerator bypass pipe connected to a condensate supply pipe and a downcomer pipe with a circulation pump, bypassing the aspirator, condensate flowing through the condensate supply pipe and condensate flowing through the deaerator bypass pipe; In the method of preventing water hammer in the deaerator water supply pipe for preventing the occurrence of water hammer at the junction of the above, a part of the condensate supplied by the condensate pump is mixed with the condensate flowing through the deaerator bypass pipe. A method for preventing water hammer in a deaerator water supply pipe. 2. A condensate supply pipe for supplying condensate from a condenser to a deaerator by a condensate pump, a precipitation pipe for guiding the degassed condensate in the deaerator to a boiler feed pump, A deaerator bypass pipe connected to a condensate supply pipe and a downcomer pipe with a circulation pump, bypassing the aspirator, condensate flowing through the condensate supply pipe and condensate flowing through the deaerator bypass pipe; In the water hammer prevention piping system of the deaerator water supply piping to prevent the occurrence of water hammer at the confluence of the condensate, connect the condensate supply piping at the condensate pump outlet and the deaerator bypass piping at the circulation pump outlet. A water hammer prevention piping system for a deaerator water supply pipe, which is provided with a water injection pipe for allowing a part of the condensate to flow from the condenser.