JPH094415A - Steam turbine condensation system - Google Patents

Abstract

PURPOSE: To early discharge non-condensation gas of a low pressure supply water heater and effectively recover heat energy of vent steam from the low pressure supply water heater. CONSTITUTION: In a steam turbine condensation system, condensed water from a condenser 4 is supplied to a steam generator (boiler) 1 through a ground steam condenser 5 and a low pressure supply water heater 6. In such a steam turbine condensation system, a vent piping 11 of the low pressure supply water heater 6 is connected to the ground steam condenser 5. Non-condensation gas from the low pressure supply water heater 6 and steam are introduced to the ground steam condenser 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam turbine condensate system of a thermal power plant, a nuclear power plant or the like.

[0002]

2. Description of the Related Art In plants equipped with steam turbines such as thermal power plants and nuclear power plants, in order to maintain heat transfer performance between extracted steam and condensate in a low pressure feed water heater, It is necessary to vent the non-condensable gas and discharge it outside the system. In the conventional steam turbine condensing system, the air vent pipe is connected to the condenser.

The conventional steam turbine condensate system described above is shown in FIG. A moisture separator / heater 3 and a condenser 4 are provided on the downstream side of the steam turbine 2 into which the steam generated by the boiler 1 which is a steam generator is introduced, and the condensed water obtained by the condenser 4 is , The ground steam condenser 5 to which the ground steam of the steam turbine is supplied by the condensate pump 9, the low-pressure feed water heaters 6 of multiple stages to which steam such as extraction steam of the steam turbine is supplied, and the deaerator 7 to supply water The high pressure feed water heater 8 is supplied to the upper boiler 1 by a pump 10.

Condensate from the condenser 4 is supplied to the upper boiler 1 which is sequentially heated by the gland steam condenser 6, the low pressure feed water heater 6 and the high pressure feed water heater 8.

Each low-pressure feed water heater 6 is connected to the condenser 4 by a vent pipe 11, and the non-condensable gas in the low-pressure feed water heater 6 is condensed by the vent pipe 11 as described above. Is discharged inside. In addition, 12 is an exhaust fan of the grand steam condenser.

[0006]

In the above conventional steam turbine condensate system, as described above, the low pressure feed water heater is used to ensure the heat exchange performance of the extracted steam and the condensed water in the low pressure feed water heater. Is connected to the condenser via a vent pipe, and the non-condensed gas in the low-pressure feed water heater is discharged into the condenser.

Therefore, the non-condensed gas of the low-pressure feed water heater and a large amount of steam accompanying it are vented, and the thermal energy of the vent steam from the low-pressure feed water heater is discharged to the condenser. Not being used effectively.

Further, the non-condensable gas in the low-pressure feed water heater needs to be discharged to the outside of the system, but in the current system configuration, the non-condensed gas is brought into the condenser, which is transferred to the condenser tube. It is not desirable from the viewpoint of ensuring thermal performance.

The present invention is intended to provide a steam turbine condensate system capable of solving the above problems.

[0010]

The present invention provides a steam turbine condensate system in which condensate from a condenser is supplied to a steam generator via a gland steam condenser and a low pressure feedwater heater,
The vent pipe of the low-pressure feed water heater is connected to the gland steam condenser.

[0011]

In the present invention, since the vent pipe of the low-pressure feed water heater is connected to the gland steam condenser, the non-condensed gas in the low-pressure feed water heater is not brought into the condenser and is grounded by the vent pipe. It is introduced into the steam condenser and is effectively discharged from the main cycle (steam, condensate system) to the outside of the system by the fan of the grand steam condenser. Further, with respect to the steam discharged from the low-pressure feed water heater to the vent pipe, the latent heat of the steam can be effectively recovered in the gland steam condenser.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG. In this embodiment, each vent pipe 11 of the low-pressure feed water heaters 6 in multiple stages is connected to the gland steam condenser 5. In other respects, there is no difference from the steam turbine condensate system shown in FIG. 4, and in FIG. 1, the same parts as in FIG. 4 are assigned the same reference numerals.

In the present embodiment, the vent steam from the low-pressure feed water heater 6 is introduced into the gland steam condenser 5 through the vent pipe 11 together with the non-condensable gas, and in addition to the heat of the gland steam of the steam turbine, The heat of the vent steam is recovered by the gland steam condenser 5, and the efficiency of the plant can be improved.

The vent steam introduced into the gland steam condenser 5 exchanges heat with the condensate and is discharged as a condensed drain, and also the non-condensable gas brought into the gland steam condenser 5 together with the vent steam. Is quickly and reliably discharged out of the system by the exhaust fan 12 of the gland steam condenser 5. As a result, the occurrence of ammonia attack on the tube of the low-pressure feed water heater 6 can be prevented, and the non-condensable gas is not introduced into the condenser 4 to ensure the heat transfer performance in the condenser 4. be able to.

In addition, in the gland steam condenser 5,
Although the vent steam of the low-pressure feed water heater 6 flows in to increase the amount of heat treated, the heat transfer area of the gland steam condenser 5 should be commensurate with this amount of heat treatment, and the capacity of the exhaust fan 12 should be low. The capacity of the gland steam condenser 5 can be increased in the conventional way of thinking by making it compatible with the increase due to the non-condensable gas from the heater 6.

A second embodiment of the present invention is shown in FIG. In this embodiment, the vent pipe 11A of the low-pressure feed water heater 6A on the most upstream side is connected to the condenser 4 similarly to the conventional one shown in FIG. 4, and low-pressure feed water having a large heat recovery effect on the downstream side is connected. The vent pipe 11 of the heater 6 was connected to the gland steam condenser 5 as in the first embodiment.

Also in this embodiment, the same operation and effect as those of the first embodiment can be obtained.

A third embodiment of the present invention is shown in FIG. In this embodiment, in addition to the gland steam condenser 5 to which the vent pipe 11 of the low-pressure feed water heater 6 is connected in the second embodiment, a gland steam condenser to which the vent pipe 11 is not connected is used. 5A is arranged in parallel with the gland steam condenser 5 so that the condensate flow rate increases in accordance with the load.

Also in this embodiment, the same operation and effect as those of the second embodiment can be obtained.

[0020]

According to the present invention, since the vent pipe of the low-pressure feed water heater of the steam turbine condensate system is connected to the gland steam condenser, the non-condensed gas in the low-pressure feed water heater is a gland steam condenser. After that, it can be effectively discharged to the outside of the system early and damage to the tube of the low-pressure feed water heater, such as ammonia attack, can be prevented. Further, since the non-condensed gas in the low-pressure feed water heater is discharged to the outside of the system via the gland steam condenser without being brought into the condenser, heat transfer performance in the condenser can be ensured.

Further, by introducing the steam discharged from the low-pressure feed water heater into the vent pipe together with the non-condensable gas into the gland steam condenser, the thermal energy can be effectively recovered and the plant efficiency can be improved. Can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a second embodiment of the present invention.

FIG. 3 is a schematic diagram of a third embodiment of the present invention.

FIG. 4 is a schematic diagram of a conventional steam turbine condensate system.

[Explanation of symbols]

 1 Boiler 2 Turbine 3 Moisture Separation Heater 4 Condenser 5,5A Ground Steam Condenser 6,6A Low Pressure Water Heater 7 Deaerator 8 High Pressure Water Heater 9 Condensate Pump 10 Water Pump 11,11A Vent Pipe 12 Grand steam condenser exhaust fan

Claims (1)

[Claims] 1. In a steam turbine condensate system in which condensate from a condenser is supplied to a steam generator through a gland steam condenser and a low-pressure feedwater heater, a vent pipe of the low-pressure feedwater heater is connected to the gland. A steam turbine condensing system characterized by being connected to a steam condenser.