Abstract: A water quality diagnosis method, includes: a step of obtaining a measurement value of electrical conductivity of a sample water derived from a steam or a circulating water obtained from a steam turbine plant using ammonia as a water conditioner and a measurement value of pH of the sample water; and a determination step of determining presence or absence of abnormality of water quality of the steam turbine plant by using at least a first determination condition of whether the measurement value of the electrical conductivity and the measurement value of the pH are included in a first determination region which is set within a first correlation map of the electrical conductivity and the pH taking into account a carbonic acid concentration range where carbonic acid is dissolvable in the sample water.

Abstract: A steam turbine plant includes a chemical supply part configured to supply a pH adjuster to feedwater to a steam generator, an adjustment part for adjusting a supply amount of the pH adjuster to the feedwater by the chemical supply part, and at least one carbon steel component that includes a pipe or a device formed from carbon steel and through which the feedwater flows, the carbon steel component being configured such that an internal temperature at least partially falls within a range of not less than 120° C. and not greater than 180° C. under load operating condition of the steam turbine plant. The adjustment part is configured to, under the load operating condition, adjust the supply amount of the pH adjuster such that pH of the feedwater in each of the at least one carbon steel component is not less than 9.8.

Abstract: In a seawater leakage detection device in a feedwater system, a method for detecting seawater leakage in a feedwater system, and a steam turbine plant, an ammonia addition device configured to add ammonia as a pH adjusting agent to feedwater at an upstream side of a high-pressure drum in a feedwater line, an acid electrical conductivity meter configured to measure an acid electrical conductivity of drum water in the high-pressure drum, and a control device configured to control the ammonia addition device such that a pH value of drum water in the heat recovery steam generator expresses alkalinity equal to or greater than a preset predetermined value, calculate a chlorine ion concentration of drum water on the basis of the acid electrical conductivity measured by the acid electrical conductivity meter, and determine whether leakage of seawater is detected are provided.

Abstract: A solute concentration decision method for deciding a planned value CI of a concentration of a solute in a solution to be supplied to a first drum among one or more steam drums for temporarily containing steam generated in a boiler of a steam turbine plant includes a step of deciding the planned value CI of the concentration of the solute in the solution to be supplied to the first drum, on the basis of a target concentration of the solute in the solution in the first drum and a capacity coefficient of the solute in a drum unit including the first drum and an evaporator for generating steam contained in the first drum.

Abstract: A steam turbine plant includes a chemical supply part configured to supply a pH adjuster to feedwater to a steam generator, an adjustment part for adjusting a supply amount of the pH adjuster to the feedwater by the chemical supply part, and at least one carbon steel component that includes a pipe or a device formed from carbon steel and through which the feedwater flows, the carbon steel component being configured such that an internal temperature at least partially falls within a range of not less than 120° C. and not greater than 180° C. under load operating condition of the steam turbine plant. The adjustment part is configured to, under the load operating condition, adjust the supply amount of the pH adjuster such that pH of the feedwater in each of the at least one carbon steel component is not less than 9.8.

Abstract: In a seawater leakage detection device in a feedwater system, a method for detecting seawater leakage in a feedwater system, and a steam turbine plant, an ammonia addition device configured to add ammonia as a pH adjusting agent to feedwater at an upstream side of a high-pressure drum in a feedwater line, an acid electrical conductivity meter configured to measure an acid electrical conductivity of drum water in the high-pressure drum, and a control device configured to control the ammonia addition device such that a pH value of drum water in the heat recovery steam generator expresses alkalinity equal to or greater than a preset predetermined value, calculate a chlorine ion concentration of drum water on the basis of the acid electrical conductivity measured by the acid electrical conductivity meter, and determine whether leakage of seawater is detected are provided.

Abstract: An injection device for injecting injection fluid (chemicals) into piping through which fluid flows, the injection device comprising: an injection line through which the injection fluid flows, the injection line being connected to the piping; an injection pump disposed on the injection line; an extrusion line connected downstream of the injection pump and upstream of a target portion for air removal on the injection line; and an extrusion pump for feeding extrusion fluid to the extrusion line, wherein a discharge capacity of the extrusion pump is greater than a discharge capacity of the injection pump.

Abstract: An injection device for injecting injection fluid (chemicals) into piping through which fluid flows, the injection device comprising: an injection line through which the injection fluid flows, the injection line being connected to the piping; an injection pump disposed on the injection line; an extrusion line connected downstream of the injection pump and upstream of a target portion for air removal on the injection line; and an extrusion pump for feeding extrusion fluid to the extrusion line, wherein a discharge capacity of the extrusion pump is greater than a discharge capacity of the injection pump.