GB/T 40084-2021Guidance for energy management performance assessment in iron and steel industry (English PDF)

4.4 Assessment boundary

Determine the boundaries of energy management performance assessment according to the management responsibilities, product scope and geographic area of iron and steel enterprises.

The boundary of energy management performance assessment of iron and steel enterprises can include the main production system, auxiliary production system and subsidiary production system of the enterprise, excluding the mining and washing system.

a) Main production system: It mainly includes coking, sintering, pelletizing, iron-making, steel-making, hot rolling, cold rolling, color coating, galvanizing and other main production systems.

b) Auxiliary production system: It mainly includes auxiliary production systems such as power, power supply, water supply, oxygen production, heating power, gas, air supply, machine repair, and transportation.

c) Subsidiary production system: It mainly includes the production command system (factory headquarters) and the departments and units (such as staff canteens, workshop bathrooms) that serve production in the factory area.

5.1 Assessment preparation

Before conducting energy management performance assessment, make the following preparations:

a) Identify laws, regulations, standards and requirements from countries, industries, localities and other related parties.

b) Determine the assessment scope. Due to the differences in the processes and products of iron and steel enterprises, the energy management performance assessment scope can include all or part of the systems within the scope of assessment boundary of 4.4; it is an independent accounting unit.

5.4 Energy performance assessment

5.4.2 Assessment indicator calculation method

5.4.2.1 Calculation method of quota indicators

The sintering process energy consumption, the pelletizing process energy consumption, the blast furnace process energy consumption, and the converter process energy consumption are calculated according to the method that is specified in GB 21256; the coking process energy consumption is calculated according to the method that is specified in GB 21342.

If the enterprise's location has issued a local quota standard for energy consumption of the process, it shall be calculated according to the calculation method in the local quota standard.

5.4.2.2 Calculation method of efficiency improvement indicators

Calculate indicators such as the comprehensive energy consumption per ton of steel, the hot rolling process energy consumption, the cold rolling process energy consumption, the electricity consumption per ton of steel, and the new water consumption per ton of steel of the enterprise, according to the product output and energy consumption in the energy balance sheet of the enterprise.

The comprehensive energy consumption per ton of steel is calculated according to the method that is specified in GB/T 2589. The indicator improvement rate is calculated according to Formula (1):

Where: Y - indicator improvement rate; Apre - indicator of the previous year; A - Assessment annual indicators.

5.4.2.3 Calculation method of task indicators

Comparing with the energy-saving target liability statements that are signed by the enterprise and the government authority, the annual energy-saving plan targets that are issued by the enterprise, and according to the data in the enterprise "energy balance sheet", calculate and assess the completion rate of the annual task indicators.

5.4.4.3 Validity assessment of energy performance indicators

The validity of energy performance indicators depends on the validity and reliability of basic data and related documents.

In the assessment process, identify the factors that affect the validity of energy performance indicators. Possible influencing factors include:

-- The validity and reliability of basic data and related documents cannot be fully verified;

-- Major changes have taken place in the manufacturing techniques and product structure;

-- Major changes have taken place in the main equipment;

-- Major changes have taken place in the production organization and production scale;

-- Major changes have taken place in the energy structure;

-- Force majeure, etc.

When the identified influencing factors have a significant impact on the validity of energy performance indicators, they shall be assessed and explained.

5.4.4.4 Output of energy performance assessment

Use the method of sub-item scoring to assess and score the assessment indicators in accordance with 5.4.3; obtain the total score after summarizing.

The assessment results are divided into four grades according to the total score, as shown in Table 4. […]