Tubine Generator System

TUBINE GENERATOR SYSTEM

TURBINE SYSTEM

The power unit is installed with aК-1000-50/3000-2 high-speed condensing turbineOperating on saturated steam,With non-controlled steam bleeds,With moisture separation and single-stage steam reheating,With a rotational speed of 3000 rpm.

TURBINE SYSTEMS

The Turbine Systems consists of:A single double flow HP Turbine (HPC)A single stage combined Seperator and ReheatorThree LP Turbines (LPC)Three CondensersRegenerative Feed Heating System

FROM STEAM GENERATORS

TO STEAM GENERATOR

HP TURBINE LP TURBINE 1 LP TURBINE 2 LP TURBINE 3

COND. PUMPS STAGE 1

GSC

DEMINZR

LPH 1 LPH 2 LPH 3

COND. PUMPS STAGE 2

LPH 4

DEAERATOR

TFP

AUX FP

HPH 1

LCV

BASIC FEED WATER CYCLE Fig.No.7

REHEATER MOIST. SEPRTR

HPH 2

TURBINE SYSTEMS

Shaft Lubricating oil SystemShaft Turning Gear SystemTurbine Governing SystemC & I Systems for control and monitoring the Turbo-Generator

GENERATOR SYSTEMS

The Generator Systems consist of a single a TVV-1000-2/24 alternator withStator Water Cooling SystemRotor Hydrogen Cooling SystemShaft Sealing SystemGenerator Excitation SystemGenerator control SystemC & I SystemsPower evacuation System

TURBINE SYSTEM

The steam from the Four steam generators is supplied via Main Steam Isolating Valve (MSIV) and a Main Isolating Valve (MOV) to the HPC.The function of the MSIV AND MOV are To Isolate the SG in case of tube leaksTo Isolate the SG in case of steam line rupture to prevent fast cooling of the reactor

SG SAFETY RELIEF VALVES BRU-A

BRU-A

BRU-K

BRU-A BRU-K

BRU-A

TO MAIN CONDENSER

TO HP TURBINE

TO HP TURBINE

MSIV MO VALVE

To atmosphere To atmosphere

Secondary Steam Supply System - Fig. No. 6

TURBINE SYSTEM

The steam then passes through the four Stop valve and Throttle Governing valve units on each steam line and enters the HPC.

TURBINE SYSTEMAfter the HPC the steam goes through four steam lines (two lines per each exhaust from the HPC) to the steam separator-reheater for separation and intermediate reheating, both are single-staged. On passing separation and reheating, the steam goes, through the LP valve units, to the LPCs. From the LPC the steam is discharged into three condensers. The condensers are basement-type, transverse, with titanium tubes.

Regenerative Feed Heating System

The basic regeneration scheme is 4LPH+D+2HPH.The low-pressure heater LPH-1 is a surface type, horizontal, built in the condenser. The LPH-2 is of mixing type. LPH-3 and LPH-4 are of surface type.The HPHs are vertical and chamber-type. The tubing is made of stainless steel. Each housing of the HPH has an in-built drain cooler.


TO STEAM GENERATOR

HP TURBINE LP TURBINE 1 LP TURBINE 2

COND. PUMPS STAGE 1

LPH 2 LPH 3 LPH 4

DEAERATOR

TFP

AUX FP

HPH 1

LCV


HPH 2

TURBINE SYSTEM

The condensers steam receivers, which are equipped with receive steam from the steam generators dumped into the condenser through the Steam Dump Valves (BRU-K).Also, the excess steam can be relieved to the atmosphere through Steam Discharge Valves (BRU- A) and by Safety Relief Valves.The Safety Relief Valves are Instrumented relief valves called Pulse Safety Devices (PSD)

SG SAFETY RELIEF VALVES BRU-A

BRU-A

BRU-K

BRU-A BRU-K

BRU-A

TO MAIN CONDENSER

TO HP TURBINE

TO HP TURBINE

MSIV MO VALVE

To atmosphere To atmosphere

Secondary Steam Supply System - Fig. No. 6

TURBINE SYSTEMS

WE NOW PROCEED TO DESCRIBE THE FUNCTIONAL DETAILS OF THE VARIOUS SYSTEMS.

Turbine Bypassing System (MAN)

The turbine bypassing system is intended for: Steam dump from the steam generators to the turbine condensers via fast-acting steam dump valves with discharge to the turbine condensers (BRU-K) during load through-off for prevention of an excessive pressure rise in the steam generators to exclude actuation of the Safety Valves and Atmospheric Dump Valves (BRU-A);

Turbine Bypassing System (MAN)

Steam removal from the steam generators in the unit startup and shutdown modes; Pressure regulation in the secondary circuit; Maintenance of the reactor thermal power at the specified level with a change in the turbine’s electrical load.

Live Steam Line System (LBA)

The live steam line system is designed for feeding live steam from steam generators to the stop and control valves in the turbine high pressure cylinder (HPC) Besides, the system provides:

Steam dumping to the turbine condensers or to atmosphere in case of load through-off of the power unit load and in case of scheduled or emergency cooling down;


Protection of the steam generators and steam lines against excessive pressure rise;

Live steam supply to the auxiliary header (when steam supply from extraction line of turbine is not available);


Live steam supply to the deaerator (when steam supply from extraction line of turbine is not available);

Live steam supply to the MSR in the steam reheating system and moisture removal upstream of the turbine low-pressure cylinders (LPC);

Isolation of steam generators by fast acting isolation valves in emergency situations

Main Cooling Water System (PAB)

The main cooling water system is intended for condensation of steam and removal of heat from condensers of the turbine.The components to ensure performing of the system functions are the main cooling water pump units.

Demineralisation System (UDP)

Turbine condensate demineralizing system (LDF) is a system for maintaining secondary circuit water-chemistry regime (WCR) and to minimise deposits on steam generators (SG) heat exchanging surface, in turbines flow part and in condensate-feeding line.This is to prevent SG, secondary circuit equipments and pipelines structure materials corrosion and corrosion-erosion damage;

Main Condensate System (MAG)

The purpose of the main condensate system is as follows:

To transfer condensate to the deaerator through Unit demineralizing plant and low pressure heaters system. To control condensate flow pumped by main condensate pumps in order to maintain the level in the deaerator and in LP heaters within the preset limits.

Main Condensate System (MAG)

To provide condensate flow in recirculation line needed for normal operation of the condensate pumps of both stages when the turbine is running at no load and at low load.

The system consists ofI-st stage condensate pumps II-nd stage condensate pumps

Feed Water System (LAA/LAB)

The feed water system is designed for:Initial filling and providing the

steam generators with feed water;Level maintaining in the steam

generators;Prevention of feed water supply

in case of a steam generator overfilling;


Prevention of feed water supply to a damaged steam generator in case of the SG steam line rupture in the non disconnectable section, feed line rupture or leakage from the primary circuit to the secondary circuit;

Deaeration and regenerative heating of turbine condensate in the deaerator to provide the design rates of oxygen content in feed water (10 g/kg at most), and also accumulation of “hot” water in the deaerator;


Power unit cooling down in case of failure of auxiliary feed water pump, as well as for quick cooling of the steam generators by standby electric pump;Averaging of feed water parameters downstream of the high-pressure reheater (HPH) groups.


The LAB system consists of two basic turbine feed pumps (2 50 % capacity) and two stand-by electric feed pumps (2 25 % capacity) which pump feedwater from the Deaerator to the Steam Generators through the HP Heaters.


TO STEAM GENERATOR

HP TURBINE LP TURBINE 1 LP TURBINE 2 LP TURBINE 3

COND. PUMPS STAGE 1

GSC

DEMINZR

LPH 1 LPH 2 LPH 3

COND. PUMPS STAGE 2

LPH 4

DEAERATOR

TFP

AUX FP

HPH 1

LCV

BASIC FEED WATER CYCLE Fig.No.7


HPH 2

Auxiliary Feed Water System (LAH)

The auxiliary feedwater system is designed:To provide steam generators with feedwater in the modes of startup, shutdown in the state of “hot” standby as well as cooldown;


To provide steam generators with feedwater in case of failures accompained by the limitations in water supply from the system of the main feedwater pumps;


To supply feedwater through the deaerator of the secondary circuit for deaeration of feed water prior to filling of steam generators;To provide the after-cooling of steam generators in the water-water mode when the reactor is shut down for repair.

Turbine Main Condenser System (MAG)

Functions Besides condensation of turbine

spent steam the purpose of the main condenser system (MAG) is as follows:

To receive normal make-up water; To deaerate condensate and make-up water primarily;


To evacuate noncondensable gases; To collect drains and noncondensable gases from the regenerative system and other sources;


To receive steam from the turbine bypass system (MAN); To control level of condensate in the hotwells in order to ensure steady operation of the condensate pumps under steady and transient conditions.

Condenser vacuum system

FunctionsCondenser vacuum system is intended for:

Evacuation of noncondensable steam-gas mixture from turbine condensers and development of vacuum within the condenser which is necessary for reliable operation of the turbine. Development of necessary vacuum in discharge chambers of condensers when filling the condensers with water at Unit start-up and when operating at load.

Steam Generator Blowdown System (LCQ 10 – 40)

The system for steam generators blowdown is designed for the SG blowdown and supply of blowdown water for purification (LCQ50-80) with the aim to keep required water chemistry of secondary circuit. It is also used for chemical flushing and decontamination of the steam generators.

Turbine Governing System

The turbine is equipped with an electro hydraulic system of automatic governing (AGS) and protection developed on the basis of designs tested in governing systems of turbines К-1000-60/3000 operating at nuclear power plants. The system carries out the following functions: Turbine running up by operator's command from the control desk.


Changing rotational speed by commands of an automatic synchronizer and keeping of rotational speed in the process of synchronization. Keeping the given turbine output; Creation of loading rate given by an operator in case of scheduled change of load;


Keeping the given live steam pressure; Turbine change over to station service load keeping rated rotational speed after load drop; Switching of controllers (load, live steam pressure) depending on operating conditions of the power unit and in interaction with reactor controller;


Analysis of temperature stresses in critical parts of turbine structure; Keeping the rated rotational speed of the turbine.

Valve name Closing time, not over than

HP stop valve 0,8 s

HP governing valve

0,4 s

LP stop valve 1 s

LP governing valve

1 s

Discharge valve

5 s


Turbine Sealing System

Functions.

The Turbine sealing system is intended as follows: To prevent steam leakage from the turbine valve stems. To remove steam-air mixture and to supply it to the gland steam condenser (GSC).

Turbine Sealing System

Sealing of the turbine flow path to prevent steam leakage into the machine hall through the clearances of the turbine cylinder shaft end glands as well as the ingress of air into the casings when there is vacuum inside them.

Documents

Tubine Generator System