Power plant analysis – Quality control in power plants (process water, turbine oils, fuels, and operating materials)
48Pages

Power plant analysis Quality control in power plants (process water, turbine oils, fuels, and operating materials)

• is the global market leader in titration • offers a complete portfolio for NIR and Raman analysis, in addition to all of the methods of • ion analysis – titration, voltammetry, and ion chromatography • is a Swiss company and manufactures exclusively in Switzerland • grants a 3-year instrument warranty and a 10-year warranty on chemical suppressors for anion chromatography • provides you with unparalleled application expertise • offers you more than 1800 applications free of charge • supports you with dependable on-site service worldwide • is not listed on the stock exchange, but is owned...

Metrohm – customized analysis for water, turbine oil, fuels, and operating materials in power plants Energy and power plants Energy supply has become a major issue of modern times. The importance of energy even plays a role in Greek my­­ thology. Zeus withheld fire from humanity, thus re­­ mov­­­­ ing all prospects of civilization. But the humans had Pro­­ me­ theus on their side: he stole fire from the gods and gave it back to mankind. Unfortunately, Prometheus is no lon­­ here to help us. Humankind has had to fend for ger itself by developing power plants to convert kinetic (wind, water)...

Power plant analysis 04 I. Process water Water circuits in thermal power plants Thermal power plants use the heat generated by combustion or nuclear fission to produce steam, which is fed into a turbine driving a generator that converts the me­­ chanical energy into electrical energy. Downstream of the turbine, the steam is condensed to water in a condenser. This water is fed into a feed tank from where it is pumped back into the steam boiler. Cooling water flows through the condenser in a separate circuit and removes the heat of condensation released by the steam via a heat exchanger....

Water-steam circuit pH value (pp. 6–7) Conductivity (p. 7) Total hardness (pp. 10–11) Sodium (pp. 14, 17) Silica (p. 14) Phosphate (p. 14) Hydrazine (p. 15) Amines (p. 17) Iron (pp. 16, 20–21) Copper (pp. 16, 20–22) Zinc (pp. 16, 20, 22) Cobalt (pp. 16, 20) Nickel (pp. 16, 20, 22) Corrosive anions (pp. 17–19, 23) Cooling water circuit pH value (pp. 6–7) Conductivity (p. 7) Total hardness (pp. 10–11) Chloride (p. 11) Corrosion inhibitors (p. 12) Heavy metals (p. 12) Analytical parameters monitored in a power plant with two water circuits Primary circuit Water-steam circuit pH value (pp. 6–7)...

I. Process water in power plants 06 pH value and conductivity All thermal power plants convert energy generated by combustion processes or nuclear fission into heat that is then used to vaporize water as an operating fluid. Highpressure superheated steam is fed to the blades of a high-pressure turbine causing it to rotate, thus producing electricity via a coupled generator. The steam is expanded in the low-pressure zone of the turbine and then condensed to water in a cooled condenser. This condensate is purified, preheated, and pumped as feed water to the evaporator. The primary cooling...

Conductivity The conductivity indicates the amount of dissolved minerals. It is a measure of the water purity and is one of the most important parameters for any chemical control program in a power plant. It is determined at numerous sampling points in the power plant, for example, in the cooling water circuit, in feed and makeup water, at the outlet of the condensate pump, and in the primary circuit of a pressurized water reactor. In high-purity process water, it reflects the amount of added additives such as ammonium or amines. A sudden increase in the conductivity often indicates a...

Corrosion of metals in power plants is a commonly oc­­ cur­­ ring phenomenon due to the continuous contact of the metal with a corroding environment. According to the definition in DIN EN ISO 8044, corrosion is a physicochemical interaction between a metal and its surroundings and which results in a measurable change in the material that can have a negative impact on the function of the metal or even the entire system. These interactions are usually of an electrochemical nature. The objective is to use suitable treatment and conditioning of the water to minimize the corrosion rate and the...

Hydrogen permeation in accordance with ASTM G148 Electrochemically generated hydrogen, absorbed by some metallic surfaces, can permeate the material chang­ ing its mechanical properties. Determination of hydrogen permeation in metals is thus an important pa­­ meter in ra­­ corrosion research. Electrochemically control­­ hydrogen led per­­mea­tion is measured using a Devan­a­than-Stachurski (double) cell. It comprises two separate electrolytic cells 09 that are separated by a membrane made from the metal being investigated. Hydrogen is generated electrochemically at the cathode, whereas the...

Cooling water is used to condense the exhaust steam from the turbine to water, which is then sent back to the water-steam circuit as feed water. The heat of condensation from the steam is transferred to this cooling water as it flows through the kilometers of piping – usually made of titanium – in the condenser. The cooling water is cool­ ed either by once-through cooling, in which the water is taken from a river and returned at a slightly higher temperature, or in a circuit in a cooling tower. In a wet cooling tower, this heat is dissipated into the atmosphere: as the warmed-up cooling...

Colorimetric determination of the water hardness – process parameters In addition to determination with an ISE, described on page 10, the water hardness can also be determined by colorimetry. After adding the indicator hydroxynaphthol blue, a red complex forms at pH values above 7. Adding EDTA solution changes the color back to blue. The color change is proportional to the concentration of alkaline earth metal ions. Determinations in the sub-µg/L range can be conveniently carried out in only 10 minutes using an ICON Analyzer, recently developed by Metrohm Process Analytics. The ICON...