JP3875471B2 - Condenser vacuum pump system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a condenser vacuum pump system for extracting air from a steam turbine condenser, and to an anti-freezing method and apparatus for an air ejector attached to the condenser vacuum pump.
[0002]
[Prior art]
An example of anti-freezing measures for an air ejector attached to a conventional condenser vacuum pump is shown in FIG.
[0003]
According to FIG. 3, the air ejector 3 can be prevented from freezing by turning on the air ejector nozzle heater 8 and the diffuser heater 9 while the pump is stopped, thereby reducing the service life due to the deterioration of the heaters 8 and 9 due to abnormal heating. , 9 may be disconnected, so that the temperature switch 10 operates according to the conditions during the operation of the vacuum pump 4 and the AND condition of the ambient temperature around the pump or the temperature of the air ejector metal lowering, and the nozzle heater 8 and the diffuser heater 9 The power is turned on and the air ejector 3 is heated to prevent freezing. Moreover, since the heaters 8 and 9 are positioned as important heaters from the viewpoint of preventing a vacuum drop when the plant operation is continued, the heater current monitoring device 11 for confirming the operating state of the heaters 8 and 9 themselves, And alarm devices associated therewith.
[0004]
[Problems to be solved by the invention]
In the prior art, after the power-on conditions for the nozzle heater and the diffuser heater are established, the heater is turned on, and it takes some time for the heater itself to reach a temperature that prevents freezing. In the standby state of the ejector, when the vapor accompanying the non-condensable gas sucked by the vacuum pump is condensed in the air ejector and a drain pool is formed, air supersonic flow in the drain and air ejector immediately after the vacuum pump is started. Freezing is started inside the air ejector due to the temperature reducing effect of the above, and the inside of the ejector is blocked by freezing before the air ejector itself is heated. In addition, the heater is installed for the purpose of preventing freezing, and does not have a heater capacity for thawing the inside of the frozen ejector, leading to a vacuum drop in the condenser.
[0005]
In addition, since the heater itself is a consumable item, it is necessary to install a heater current monitoring device, and the structure of the anti-freezing system is complicated from the viewpoint of improving reliability.
[0006]
An object of the present invention is to provide a condenser vacuum pump system with a simple and inexpensive anti-freezing measure without having another power source / control system and consumables.
[0007]
[Means for Solving the Problems]
A feature of the present invention is that a non-condensed air extracted from a steam turbine condenser is sucked by a vacuum pump through an air ejector, and the air is discharged out of the system through a separator tank. During the operation of the pump, the sealed water heated by the vacuum pump is supplied to a jacket provided in the air ejector.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
A reference example of the present invention will be described with reference to FIG.
[0010]
FIG. 1 shows an overall system diagram of a condenser vacuum pump system. According to this figure, non-condensed air extracted from a condenser 1 is sucked by a vacuum pump 4 through an air ejector 3. Then, it is discharged out of the system through the separator tank 5. Also, the sealed water in the condenser vacuum pump system is received after the sealed water supplied from another water system is received by the separator tank 5, the pressure is increased by the sealed water circulation pump 6, and the sealed water is cooled by the sealed water cooler 7. The circulation system is supplied to the vacuum pump 4 and returns to the separator tank 5 from the vacuum pump 4.
[0011]
In this operation flow, the condenser vacuum pump 4 in standby operation is pumped into the air ejector 3 because the inlet valve 2 is fully closed and the system in the condenser vacuum pump system is in the atmospheric pressure state. When the vapor accompanying the non-condensed air sucked by 4 is condensed and drainage is generated, the drain passes through the pipe 12 due to the water head difference in the condenser vacuum pump system, and the fineness provided in the pipe 12 is reduced. By flowing into the separator tank 5 via the differential pressure check valve 13, it is possible to discharge the drain generated in the air ejector 3, and when the condenser vacuum pump 4 is activated, the air ejector 3 Since the vacuum is applied and the separator tank 5 is at atmospheric pressure, a pressure difference occurs, and the fine differential pressure check valve 13 operates in the closing direction, so that the backflow of drain from the separator tank 5 to the air ejector 3 is prevented. Therefore, the air ejector immediately after the start of the condenser vacuum pump standby can be realized with a simple and inexpensive configuration without adding a motor operated valve for discharging the drain inside the air ejector 3 and an interlock for controlling them. It is possible to prevent the air ejector 3 from freezing due to a drain pool in the interior 3.
[0012]
The actual施例of the present invention will be described with reference to FIG.
[0013]
During the normal operation, the condenser vacuum pump 4 is configured so that, in the sealed water circulating in the condenser vacuum pump system, the compression heat generated when the air is discharged in the vacuum pump 4 and the heat input to the vacuum pump motor. The sealed water heated by such as the like is supplied from the lower part of the sealed water jacket 16 provided in the air ejector 3 through the orifice 15 for preventing the overload of the sealed water circulation pump 6 provided on the sealed water supply pipe 14. By passing the return pipe 17 returned to the separator tank 5 from the uppermost part of the jacket, the entire air ejector 3 can be warmed up, and the antifreeze heater for the air ejector 3 and the instruments, interlocks and heaters for controlling them. The air ejector 3 has a simple and inexpensive configuration without using monitoring equipment and utility of the heater power supply, no consumables. It is possible to prevent freezing.
[0014]
【The invention's effect】
According to the present invention, it is possible to provide a condenser vacuum pump system with a simple and inexpensive anti-freezing measure without having another power source / control system and consumables.
[Brief description of the drawings]
FIG. 1 is a system diagram illustrating prevention of air ejector freezing when a condenser vacuum pump is started in a reference example of the present invention.
FIG. 2 is a system diagram illustrating prevention of air ejector freezing during operation of the condenser vacuum pump in the embodiment of the present invention.
FIG. 3 is a system diagram illustrating air ejector freezing prevention during operation of a condenser vacuum pump according to a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Condenser, 2 ... Inlet valve, 3 ... Air ejector, 4 ... Vacuum pump, 5 ... Separator tank, 6 ... Sealed water circulation pump, 7 ... Sealed water cooler, 8 ... Nozzle heater, 9 ... Diffuser heater, DESCRIPTION OF SYMBOLS 10 ... Temperature switch, 11 ... Heater power supply monitoring device, 12 ... Air ejector drain line, 13 ... Fine differential pressure type check valve, 14 ... Sealed water supply piping, 15 ... Orifice, 16 ... Air ejector jacket, 17 ... Sealed water return Piping.

Claims (2)

In the anti-freezing method of the condenser vacuum pump system in which non-condensed air extracted from the steam turbine condenser is sucked by a vacuum pump through an air ejector, and the air is discharged out of the system through a separator tank.
During the operation of the vacuum pump, the sealed water heated by the vacuum pump is boosted by the sealed water circulation pump via the separator tank, and supplied to the jacket provided in the air ejector via the sealed water supply pipe. A method for preventing freezing of a condenser vacuum pump system. In the condenser vacuum pump system, the non-condensed air extracted from the steam turbine condenser is sucked by a vacuum pump through an air ejector, and the air is discharged out of the system through a separator tank.
During the operation of the vacuum pump, a sealing water supply pipe for supplying the sealing water heated by the vacuum pump to the jacket provided in the air ejector is connected between the air ejector jacket and the separator tank, and further the air ejector jacket and A condenser vacuum pump system characterized in that the separator tanks are connected by a sealed return pipe.

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