Section 1. Introduction

2022 ◽  
pp. 1-2
Author(s):  

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.

2022 ◽  
Author(s):  

The Water Technology Subcommittee of the ASME Research and Technology Committee on Water and Steam in Thermal Systems, under the leadership of Mr. Robert D. Bartholomew has revised the Consensus on Operating Practices for the Control of Feedwater Boiler Water Chemistry in Modern Industrial Boilers, first published in 1979 with prior revisions published in 1994 and 1998. The task group consisted of a cross section of manufacturers, operators, chemical treatment contractors and consultants involved in the fabrication and operation of industrial and institutional boilers. Members of this group are listed in the acknowledgments. This current document is an expansion and revision of the original, with reordered and modified texts where considered necessary. While significant revisions have been incorporated, it is recognized that there are areas of operating practice not addressed herein. Additional information is available from the references. It is the plan of the ASME Research Committee to continue to review this information, and revise and reissue this document as necessary to comply with advances in boiler design and water conditioning technology.


2022 ◽  
pp. 28-30
Author(s):  

Consensus water chemistry controls for the six types of steam generator systems are presented in Tables 1 through 7. The tabulated information is categorized according to operating pressure ranges because this is the prime factor that dictates the type of internal water chemistry employed, the normal cycles of feedwater concentration, the silica volatility, and the carryover tendency. The difference between steam and water densities decreases with increasing pressure and temperature; therefore, separating the steam/water phases completely in the boiler drum becomes increasingly difficult to achieve. Since the tendency to carryover is greater at higher operating pressures, it is necessary to maintain lower boiler water contaminant concentrations to meet the same steam purity target.


2015 ◽  
Vol 62 (5) ◽  
pp. 322-326 ◽  
Author(s):  
Zhiping Zhu ◽  
Xiaocui Jiao ◽  
Xueying Tang ◽  
Haiwei Lu

Purpose – The purpose of this paper was to investigate the effects of SO42− concentration on the corrosion behaviour of T23 and T12 steels in simulated water chemistry condition solution of 600 MW fossil-fired power boilers. Design/methodology/approach – The influence and mechanism of SO42− ions on the pitting corrosion of T23 and T12 steels in simulated oxygenated treatment water chemistry solution was studied using electrochemical potentiodynamic polarization scans and electrochemical impedance spectroscopy. Findings – The results showed that T23 and T12 were susceptible to pitting corrosion in the simulated solution with full SO42− concentration for the competitive adsorption of OH− and SO42− on the surface of steels. The pitting sensitivity of the steels improved with increasing SO42− concentration. The corrosion resistance for SO42− of T23 was stronger than that for T12. Originality/value – This study is an attempt to provide direction for regulating the concentration of SO42− in boiler water and for selecting the material for boiler water wall tubes.


Author(s):  
V. Voloshchuk ◽  
Eu. Nikiforovich

The most widespread approaches to the study of thermal systems involve the iterative implementation of the following steps: thermodynamics, heat and mass transfer, hydrodynamics, economics and ecology. Such methodology cannot combine economic, environmental and thermodynamic aspects from the beginning of the analysis. It does not provide information concerning not only external, but also internal, caused by thermodynamic inefficiencies of system components, impact factors on economic and ecological characteristics. Modeling methods based on the combined application of the First and Second Laws of Thermodynamics (methods of entropy and exergetic analysis), and their combination with economic and environmental assessment make it possible to identify the location, magnitude, causes, costs and environmental impact of thermodynamic inefficiencies in an energy conversion system. The paper proposes the improvement of methods for modeling thermal systems on the base of exergy analysis. It has been shown that combining exergetic, economic and ecological assessment can significantly simplify tasks of finding parameters and structure of the studied system. Examples of implementation of such studies have been presented.


Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 289 ◽  
Author(s):  
Cuneyt Uysal ◽  
Ho-Young Kwak

Power plants or thermal systems wherein products such as electricity and steam are generated affect the natural environment, as well as human society, through the discharging of wastes. The wastes from such plants may include ashes, flue gases, and hot water streams. The waste cost is of primary importance in plant operation and industrial ecology. Therefore, an appropriate approach for including waste cost in a thermoeconomic analysis is essential. In this study, a method to take waste cost into account in thermoeconomics to determine the production cost of products via thermoeconomic analysis is proposed. The calculation of the waste cost flow rates at the dissipative units and their allocation to system components are important to obtain the production cost of a plant.


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