ISO/TS 21152:2024 火力発電所の冷却水を循環させる節水技術の指導 | ページ 2

3.1 用語と定義

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives ).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents . ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html .

This document was prepared by Technical Committee ISO/TC 282, Water reuse, Subcommittee SC 4, Industrial water reuse.

Introduction

Water plays an important role in transferring energy, cooling and cleaning in the process of thermal power generation. According to the statistics of the International Energy Agency (IEA) and China Water Resources Bulletin, fossil fuel power generation used approximately 189,6 billion cubic metres of freshwater in 2021, accounting for almost 50 % of global energy system freshwater withdrawals and 5 % of total global freshwater withdrawals. In China, water withdrawal for thermal power generation in 2021 accounted for approximately 17,7 % of the industrial water withdrawal, of which cooling water in thermal power plants accounted for approximately 50 %. To save water resources, improve circulating cooling water use efficiency and help thermal power plants to enhance water conservation, work efficiently and orderly, and thus improve the economic and social benefits of thermal power plants, it is important to formulate guidance for the conservation of water used as circulating cooling water in thermal power plants.

The quantity of circulating cooling water used in thermal power plants ranges from tens to hundreds of thousands of cubic metres based on their operating capacity. The reduction of circulating cooling water use should consider the water quality, pipe materials, water treatment, chemicals and other factors. Meanwhile, to achieve water conservation purposes, the use of residual heat of high temperature circulating water to reduce the temperature of circulating water in the cooling tower should be considered. Cycles of concentration is an important index for evaluating water conservation of circulating cooling water, while the amount of make-up water is closely related to the cycles of concentration of circulating cooling water. The higher the concentration, the better water conservation efficiency. However, with higher concentrations, the cost and difficulty of water treatment also increase exponentially.

Circulating cooling water quality control index and water conservation processes differ based on the quality of make-up water. Researchers and engineers should standardize the water conservation process of circulating cooling water in thermal power plants by fully considering the cycles of concentration and other relevant influencing factors, to provide standardized technical guidance for the targeted stake holders (policy makers, managers, technical consultants, designers, operators of water treatment systems, etc.).

Through analysis and research on the circulating cooling water conservation technology in thermal power plants, this document sets up a scientific and objective technical control index, management guidance and implementation methods that are helpful to improve the efficiency of circulating cooling water conservation and the standardization of technical transformation of thermal power plants.

Starting from the perspective of water conservation management and technology, this document provides acceptable operation control specifications for common processes of circulating cooling water conservation for most stakeholders, to improve the operation efficiency and management level of circulating cooling water conservation, which is conducive to guiding the development of specialization, normalization and standardization of circulating cooling water conservation.

This document establishes the technical guidance and recommendations for circulating cooling water conservation technology, provides research direction of circulating cooling water conservation technology, improves the water conservation efficiency, and promotes the transformation of circulating cooling water conservation technology to higher efficiency, lower energy consumption, environment friendly and resource saving, in the end realizing sustainable development.

1 Scope

This document provides technical and management guidance for water conservation of indirect open recirculating cooling water systems in thermal power plants. It is applicable to circulating cooling systems that use surface water, underground water, reclaimed water, and treated domestic sewage from thermal power plant as the make-up water and use physicochemical treatment methods to increase cycles of concentration, thus realizing water conservation and increasing water use efficiency.

This document is applicable to recirculating cooling in thermal power plants fuelled by coal, oil, natural gas, and biomass.

2 Normative references

There are no normative references in this document.

3 Terms, definitions and abbreviated terms

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

3.2 Abbreviated terms

Bibliography