Measuring device for micro flow rate and nuclear power plant having the same

Patent metadata

Field	Value
Publication number	US-2016232997-A1
Application number	US-201514855222-A
Country	US
Kind code	A1
Filing date	Sep 15, 2015
Priority date	Feb 10, 2015
Publication date	Aug 11, 2016
Grant date	—

Abstract

Provided is a device for measuring a micro flow rate. The device includes a container having an internal space for containing a fluid flowing therein and an inflow line and an outflow line formed in communication with the internal space, a fluid level gauge configured to sense whether a level of a fluid collected in the container rises to a predetermined height to conduct or block flow of an electric current, a control valve disposed in the outflow line and configured to open or close the outflow line according to a state in which the control valve is electrically connected to or disconnected from the fluid level gauge such that the outflow line is opened or closed according to a change in the fluid level; and a control unit configured to calculate a micro flow rate of the fluid collected in the container using information acquired from at least one of the fluid level gauge and the control valve.

First claim

1 . A device for measuring a micro flow rate, the device comprising:
a container having an internal space for containing a fluid flowing therein and an inflow line and an outflow line formed in communication with the internal space; a fluid level gauge configured to sense whether a level of a fluid collected in the container rises to a predetermined height to conduct or block flow of an electric current; a control valve disposed in the outflow line and configured to open or close the outflow line according to a state in which the control valve is electrically connected to or disconnected from the fluid level gauge such that the outflow line is opened or closed according to a change in the fluid level; and a control unit configured to calculate a micro flow rate of the fluid collected in the container using information acquired from at least one of the fluid level gauge and the control valve.

2 . The device of claim 1 , wherein the control unit is configured to measure a volume of fluid discharged when the control valve is opened and a time interval between opening or closing times of the control valve and use the measured volume and time to calculate the micro flow rate of the fluid collected in the container.

3 . The device of claim 2 , further comprising a relay electrically connected between the fluid level gauge and the control valve and configured to connect wires to open the control valve when an electric current is applied.

4 . The device of claim 3 , further comprising a timer electrically connected between the relay and the control valve and configured to connect wires to open the control valve when an electric current is applied while maintaining the connection of the wires for a predetermined time when the electric current is blocked.

5 . The device of claim 4 , wherein the timer is configured to be able to adjust a delay time of wiring switching according to a change in a supply amount of the fluid flowing to the container.

6 . The device of claim 1 , wherein the fluid level gauge comprises:
a rod formed to extend in a direction of changing the level of the fluid collected in the container; a moving part floated on a surface of the fluid and formed to move back and forth along the rod; and a contact part fixedly disposed over the moving part and configured to conduct an electric current when the fluid level rises and the moving part comes in contact with the contact part.

7 . The device of claim 6 , wherein the contact part is configured to be able to adjust a separation distance from the moving part according to a change in a supply amount of the fluid flowing to the container.

8 . The device of claim 7 , wherein the control valve is configured to operate in an on-off control manner using two types of signals corresponding to contact and non-contact of the fluid level gauge.

9 . The device of claim 1 , further comprising a detour line formed to branch from the inflow line or a portion of the container and communicate with the outflow line positioned at the backend of the control valve.

10 . An apparatus for measuring a micro flow rate of condensate water in which fluid circulation forms a closed loop, the apparatus comprising:
a condenser configured to condense a transferred vapor; a steam generator configured to receive condensate water condensed by the condenser, transform the received condensate water into a vapor, and transfer the transformed vapor to the condenser; and the micro flow rate measuring device of claim 1 disposed between the condenser and the steam generator.

11 . The apparatus of claim 10 , further comprising a detour line formed to branch from the inflow line or a portion of the container and communicate with any one portion of the closed loop formed between the control valve and the condenser.

12 . A nuclear power plant comprising:
a nuclear reactor having a reactor core; a steam generator configured to receive heat generated in the reactor core and transform a coolant flowing though the steam generator into a vapor; a first heat exchanger configured to condense the vapor received from the steam generator; a cooling water storage unit formed to accommodate the first heat exchanger and at least partially immerse the first heat exchanger in cooling water stored therein; a second heat exchanger configured to receive a vapor obtained by vaporizing the cooling water stored in the cooling water storage unit, condense the received vapor to condensate water, and transfer the condensate water to the cooling water storage unit; and the micro flow rate measuring device of claim 1 disposed between the cooling water storage unit and the second heat exchanger.

13 . The nuclear power plant of claim 12 , wherein the micro flow rate measuring device is disposed below the second heat exchanger and above the cooling water storage unit.

14 . The device of claim 1 , further comprising a sub container disposed in the outflow line and formed to contain a fluid discharged when the control valve is opened.

15 . The device of claim 14 , further comprising a flow rate adjustment unit disposed in an outflow line of the sub container and configured to control a fluid discharged by the sub container.

16 . A method of measuring a micro flow rate, the method comprising:
a first step of measuring a volume of a fluid discharged when a control valve, which receives a closing or opening signal from a fluid level gauge configured to sense a change in a level of a fluid collected by a container, is opened and a time interval between opening or closing times of the control valve; and a second step of calculating a micro flow rate of the fluid collected by the container using the volume of the fluid and the time interval between the opening or closing times of the control valve.

17 . The method of claim 16 , wherein the first step comprises setting a delay time of a timer configured to delay a closing signal of the control valve applied from the fluid level gauge to the control valve by a predetermined time.

18 . The method of claim 16 , wherein the first step comprises setting a variation of the fluid level sensed by the fluid level gauge.

Assignees

• Korea Atomic Energy Res

Inventors

• KIM Myungjun
• MOON Joohyung
• Lee Heejoon
• Kim Youngin
• KIM Keungkoo

Classifications

• G01F1/007 Primary

  by measuring the level variations of storage tanks relative to the time · CPC title

• G05D7/00

  Control of flow (level control G05D9/00; control of flow ratio G05D11/00) · CPC title

• H01H35/18

  Switches operated by change of liquid level or of liquid density, e.g. float switch (by magnet carried on a float H01H36/02) · CPC title

• G21C15/00

  Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants · CPC title

• G21C17/032

  Reactor-coolant flow measuring or monitoring {(measuring volume or mass flow in general G01F)} · CPC title