DE2625607A1 - Turbine blades erosion prevention - by metering specific quantities of surfactant into the (wet) steam - Google Patents

Abstract

Redn. of erosion of turbine components esp. of blades in wet steam turbines is described in the parent patent. The improvement comprise determining the concn. of the surfactant materials metered (esp. film-forming amines and/or volatile alkaline materials) in combination with the press. and temp. and the nature of the steam expansion process as well as its (their) own characteristics. The process, esp. useful in conventional powder stations or in the sec. systems of nuclear power plants, enables better use to be made of the steam's thermal energy, thus enabling turbines of comparable power to be built lighter. During the expansion cycle, a film forms on the blades, protecting their surface and preventing depositions forming.

Description

The invention relates to a method for reducing the

Erosion of turbine parts, especially turbine blades of the Wet steam turbines that are used in nuclear power plants according to patent 107 962.

In the main patent mentioned, a method is described in which in the secondary circuit of nuclear power plants with pressurized water actuators or in the water-steam cycle of conventional power plants film-forming amines alone and / or volatile alkalizing agents are added. Used as film-forming amines preferably octadecylamine or, as a volatile A1 calizing agent, preferably Morpholine used. According to the process according to the invention, the film-forming Amines alone and / or volatile alkalizing agents without pressure, for example by Sucking in between the condensate pump and the condenser or by adding it to the feed water tank, or added by means of a high pressure pump.

In practice it has been shown that the conditions of use of the Procedures are very different. The parameters pressure and temperature fluctuate as well as the type of expansion process of the steam to a large extent both between the different systems even if the same unit operates differently.

However, if these parameters assume extreme values, the specified in the main patent concentration of Dosage substances not always an optimal result can be achieved. The purpose of the invention is to the aforementioned defects. remove.

The invention is based on the object of the method for reducing the erosion of turbine parts, especially turbine blades of wet steam turbines, to improve according to patent 107 962 so that even with extreme values of the pressure and the temperature of the steam and the type of expansion process of the steam The finest possible drop spectrum of the steam-water mixture and avoidance or restriction of the formation of water films is achieved.

It has been found that the concentration of the surfactants to be used Dosing substances depending on the pressure, the temperature and the type of expansion process as well as to be determined by the properties of the dosing substances themselves. The dosing points for the metering substances are chosen for the particular unit so that the surface-active Dosing substances before the expansion process in order to achieve the desired effect required amount can be added to the steam.

When using the inventive method in one with steam operated turbo unit can better utilize the thermal energy contained in the steam will. The turbines can be built lighter with the same output and as a result of the reduced erosion on the turbine blades, the service life will be elevated. By eliminating the cracks in condensation, there is no damage to the units and the risk of damage is reduced. Vv 'during the expansion process of the Working medium, the dosing substances condense on the unit surfaces Form very thin hydrophobic protective films. This creates a direct attack on the Surfaces prevented by the working medium, which for example to reduce erosion and corrosion reduction, deposit removal and prevention leads to the formation of new deposits.

Claims (2)

Claims 1. A method for reducing the erosion of turbine parts, in particular of turbine blades of wet steam turbines, according to patent 107 962, d a d u r c h g e k e n n n z e i c h n e t that the concentration of the metered surface-active substances, especially film-forming amines and / or volatile alkalizing agents, depending on the pressure, the temperature and the type of expansion process of the steam as well as depending on their properties bec. 2. The method according to claim 1, d a d u r c h g e k e n n z e i c h n e t, that the metering points for the metering substances in the respective unit so be chosen that these surfactants prior to the expansion process in the required amount can be added to the working medium.