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Condenser Water Quality Monitor

Overview

During operation of a thermal power plant, the condenser can develop a seawater leak.
If corrective action against the seawater leak is delayed, maintenance for the boiler and turbine will become necessary. This may lead to extensive problems and could result in months of plant downtime.

This type of trouble can be prevented by early action to correct the seawater leak.

Considering this fact, MHPS developed a condenser water quality monitor to eliminate the uncertainty of measurement and make it easy for operators to identify seawater leaks. You can detect local changes in water quality caused by a seawater leak by using this condenser water quality monitor.

 

Features

  • More precise measurement is possible than with conventional products
    Measurement is also possible during startup and shutdown periods, whereas a conventional acid conductivity meter cannot be used during those periods.
    Also, measurement is not affected by the presence of CO2.
    Note that the sensitivity drops for about 2 hours during vacuum ramp-up at startup.
  • Distribution measurement effective for identifying leak location
    Distributed conductivity measurement is superior to the conventional method which measures conductivity only at sampling points (for example, four points).
    In addition, the conductivity distribution inside the hot well can be displayed.

Theory of detection (conductivity distribution meter): Patent pending

Apply a voltage pulse to a sensor cable and measure the voltage change over time at the input terminal.
The voltage change over time can be converted to the water conductivity change along the sensor cable.

Theory of detection

System Configuration

The electrical characteristic of the sensor cable installed inside the condenser is analyzed. A PC continuously records the data to identify the presence of contaminated water.

System Configuration

Specifications

The specifications of a condenser water quality monitor are as described in the table below.

items descriptions
Minimum detection concentration 0.15%(concentration of seawater in condensate)*
Position resolution Maximum of 1m for the sensor cable length
Measurable distance Approximately 100m for the sensor cable length
Measurable distance Approximately 1 minute

(*) Corresponds to 10L/H leakage over one square meter for a condenser with 225m2 area and 1570m3/H flow rate.

Comparison of measurement between a "water quality monitor" unit and a salinometer

A salinometer cannot measure conductivity when the unit stops for a couple of hours until the unit restarts.
This water quality monitor can detect leaks correctly except during the vacuum ramp-up period at startup. You can, therefore, easily identify a leak that could lead to a unit shutdown.
You can also visualize the leak by displaying a two-dimensional map.

Comparison of measurement between a "water quality monitor" unit and a salinometer

Related Products

The information on this page has been authorized by MITSUBISHI HITACHI POWER SYSTEMS, LTD. For further information, please click the link below.

http://www.mhps.com/en/products/category/diasys.html

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