Long-term effects of a chemical decontamination procedure on the corrosion state of the heat exchanger tubes of steam generators

Our previous studies have revealed that a ”hybrid” structure of the amorphous and crystalline phases is formed in the outermost surface region of the austenitic stainless steel tubes of steam generators (SGs) as an undesired consequence of the industrial application of the AP-CITROX (AP: alkaline permanganate; CITROX: citric and oxalic acid) decontamination technology. The formation of this mobile oxide-layer increased the amount of the corrosion products in the primary circuit significantly, resulting in magnetite deposition on fuel assemblies. Owing to the fact that there is no investigation method available for the in-situ monitoring of the inner surfaces of heat exchanger tubes, a research project based on sampling as well as on ex-situ electrochemical and surface analytical measurements was elaborated. Within the frame of this project, comprehensive investigation of the general corrosion state and metallographic features of 36 stainless steel specimens, cut out from various locations of the 21 steam generators of the Paks NPP in the time period of 2000-2007 has been performed. The present work gives a brief overview on the general corrosion state of the heat exchanger tubes of SGs, concerning the long-term effects of the AP-CITROX procedure on the chemical composition and structure of the protective oxide-layer.

PROBLEM OF COMPUTER MODELING OF STEAM GENERATORS CHP-1 OF THE KORYAZHMA BRANCH OF ILIM GROUP AND WAYS OF SOLUTION

The concept of synthesis of a computer simulator model of a group of steam generators BKZ-160-100F is considered. An approach is formulated for constructing a mathematical de-scription structure with the possibility of parallelization of computational procedures

Section 1. Introduction

This document has been prepared by the Water Technology Subcommittee of the ASME Research and Technology Committee on Steam and Water in Thermal Systems as a consensus of proper current operating practices for the control of feedwater and boiler water chemistry in the operation of industrial and institutional, high duty, primary fuel fired boilers. These practices are aimed at minimizing corrosion, deposition, cleaning requirements, and unscheduled outages in the steam generators and associated condensate, feedwater and steam systems for boilers, and steam system components which are currently available. This publication is an expansion and revision of the operating practice consensus documents previously issued by the Committee [1-3]. The tabulated values herein update and replace the ones previously published. Titles have been edited and clarified. The text has been reordered and modified where necessary. THE TEXT IS OF PRIME IMPORTANCE AND SHOULD BE CONSIDERED FULLY BEFORE USING THE TABULATED VALUES. One Appendix has been added to provide additional guidance.

All-weather-available electrothermal and solarthermal wood-derived porous carbon-based steam generators for highly efficient water purification

Solar steam generation devices cannot work properly under weak solar light irradiation and even no solar light. Herein, an all-weather-available electrothermal and solarthermal wood-derived porous carbon-based water steam generation device...

A robust and renewable solar steam generator for high concentration dye wastewater purification

As an eco-friendly and sustainable technology, the solar-driven interfacial evaporation for water purification garners widespread attention. In the field of dye wastewater purification, some solar steam generators with catalytic degradation...