Steam generator and method of adjusting flow resistance of cooling water in steam generator

1. The steam generator, comprising:

a hollow sealed barrel;

a heat-transfer tube group that includes a plurality of heat-transfer tubes of an inverted U shape which is arranged inside the hollow sealed barrel and through which a primary cooling water flows;

a tube support that is arranged at a lower part inside the hollow sealed barrel and supports ends of the heat-transfer tubes;

an incoming water chamber that is provided at a lower end of the hollow sealed barrel and communicates with one ends of the heat-transfer tubes;

an outgoing water chamber that is provided at the lower end of the hollow sealed barrel and communicates with other ends of the heat-transfer tubes;

a secondary cooling-water supply channel that supplies a secondary cooling water to the hollow sealed barrel for performing heat exchange with the primary cooling water flowing in the heat-transfer tubes; and

a flow resistance adjusting unit that is provided in at least one of an inlet nozzle provided at the incoming water chamber and an outlet nozzle provided at the outgoing water chamber;

wherein the flow resistance adjusting unit includes a plurality of flow resistance adjusting plates with different flow path areas detachably provided in at least one of the inlet nozzle and the outlet nozzle.

2. The steam generator, comprising:

a hollow sealed barrel;

a heat-transfer tube group that includes a plurality of heat-transfer tubes of an inverted U shape which is arranged inside the hollow sealed barrel and through which a primary cooling water flows;

a tube support that is arranged at a lower part inside the hollow sealed barrel and supports ends of the heat-transfer tubes;

an incoming water chamber that is provided at a lower end of the hollow sealed barrel and communicates with one ends of the heat-transfer tubes;

an outgoing water chamber that is provided at the lower end of the hollow sealed barrel and communicates with other ends of the heat-transfer tubes;

a secondary cooling-water supply channel that supplies a secondary cooling water to the hollow sealed barrel for performing heat exchange with the primary cooling water flowing in the heat-transfer tubes;

a flow resistance adjusting unit that is provided in at least one of an inlet nozzle provided at the incoming water chamber and an outlet nozzle provided at the outgoing water chamber; the flow resistance adjusting unit includes a flow resistance adjusting gate arranged movably along a radial direction of at least one of the inlet nozzle and the outlet nozzle; and

a flowmeter that measures at least one of volume of supply water flowing from the inlet nozzle into the incoming water chamber and volume of drain water drained from the outgoing water chamber to the outlet nozzle, wherein the flow resistance adjusting unit operates the flow resistance adjusting gate based on at least one of the volume of the supply water and the volume of the drain water measured by the flowmeter.

3. The steam generator comprising a hollow sealed barrel;

a heat-transfer tube group that includes a plurality of heat-transfer tubes of an inverted U shape which is arranged inside the hollow sealed barrel and through which a primary cooling water flows;

a tube support that is arranged at a lower part inside the hollow sealed barrel and supports ends of the heat-transfer tubes;

an incoming water chamber that is provided at a lower end of the hollow sealed barrel and communicates with one ends of the heat-transfer tubes;

an outgoing water chamber that is provided at the lower end of the hollow sealed barrel and communicates with other ends of the heat-transfer tubes;

a secondary cooling-water supply channel that supplies a secondary cooling water to the hollow sealed barrel for performing heat exchange with the primary cooling water flowing in the heat-transfer tubes; and

a flow resistance adjusting unit that is provided in at least one of an inlet nozzle provided at the incoming water chamber and an outlet nozzle provided at the outgoing water chamber;

wherein the flow resistance adjusting unit includes a plurality of flow resistance adjusting cylindrical pipes arranged detachably in at least one of the inlet nozzle and the outlet nozzle.

4. The method of adjusting the flow resistance of the cooling water implemented on a steam generator including:

a hollow sealed barrel;

a heat-transfer tube group that includes a plurality of heat-transfer tubes of an inverted U shape which is arranged inside the hollow sealed barrel and through which a primary cooling water flows;

a tube support that is arranged at a lower part inside the hollow sealed barrel and supports ends of the heat-transfer tubes;

an incoming water chamber that is provided at a lower end of the hollow sealed barrel and communicates with one ends of the heat-transfer tubes;

an outgoing water chamber that is provided at the lower end of the hollow sealed barrel and communicates with other ends of the heat-transfer tubes;

a secondary cooling-water supply channel that supplies a secondary cooling water to the hollow sealed barrel for performing heat exchange with the primary cooling water flowing in the heat-transfer tubes, the method comprising adjusting at least one of the flow resistance of the primary cooling water flowing into the incoming water chamber and the flow resistance of the primary cooling water drained from the outgoing water chamber, in accordance with operating condition of the steam generator; and

stopping supply of the primary cooling water to the incoming water chamber; opening a manhole for any one of a worker and a working robot to enter at least one of the incoming water chamber and the outgoing water chamber; and adjusting at least one of an opening volume of the inlet nozzle and an opening volume of the outlet nozzle.