International Energy System Performance Evaluation Application in the Iron & Steel Industry

Transcription

1 International Energy System Performance Evaluation Application in the Iron & Steel Industry By Dr. Arvind Thekdi, E3M Inc. Dr. Ernst Worrell, Utrecht University October 19 20, 2011 Beijing, China E3M Inc. (October 19-20, 2011) 1

2 Objectives Discuss energy system performance (ESP) and energy performance indicators (ESPI) for the iron and steel industry. Levels of ESP and issues related to each level Examples of ESPI used by the industry. Challenges to development of ESPI and ESP for the iron and steel industry. E3M Inc. (October 19-20, 2011) 2

3 Energy System Performance (ESP) Energy system performance (ESP) is expressed in terms of a defined energy system performance indicator (ESPI) discussed later. ESP has been presented at several levels Industry level (i.e. iron and steel industry) Company and/or plant level (i.e. ABC integrated plant) Energy product system level (i.e. iron making) Process or equipment level (i.e. blast furnace) In most cases current value of ESP is compared with a corrected benchmark at the corresponding level. The gap between the benchmark value and current value of ESPI is used to take corrective actions and improve the ESP. E3M Inc. (October 19-20, 2011) 3

4 Energy System Performance Indicators ESPI At the industry level or plant level the indicator has been energy used per unit of production or energy intensity typically GJ/ton or Tce per ton. At the system level it can be in terms of units of energy or utility (i.e. kg of steam, liters of water etc.) used per unit of production. Example: GJ/ton or Tce/ton or Kg of steam per ton etc. At the process or process equipment level it is combination of utility and energy used per ton of product. In some cases EPI is expressed in terms of cost (i.e. RMB, $ etc.) per ton of product. These units DO NOT give correct picture since they depend on a number of variables some controllable and some not. E3M Inc. (October 19-20, 2011) 4

5 How ESPI is Used The ESPI has been used to identify gap in performance in terms of the parameters used in ESPI. The information is used to identify areas of possible improvement based on review of operating data used in calculating ESPI. Selection of corrective actions to improve value of ESPI. The actions are in the areas of operational changes, selected design changes, maintenance etc. Implementation of best practices in one or more areas mentioned above. Possible retrofit and/or addition of new subsystems such as heat recovery system, controls etc. E3M Inc. (October 19-20, 2011) 5

6 Correction Factors for ESPI The correction factors should be only those variables or factors that are uncontrollable Examples of some of the acceptable factors Raw material variation (% iron content in ore) Fuel quality changes (% ash in coal, fixed carbon change) Location and weather related issues Percent utilization Product mix changes Examples of some of the unacceptable factors Age or condition of the equipment (i.e. lack of maintenance) Lack of proper operating systems (i.e. controls) Improper operating practices (i.e. moisture removal from raw material) E3M Inc. (October 19-20, 2011) 6

7 Example of Plant Level Energy Intensity Energy-Intensity Indicator Integrated Plants, 2002 (MJ/tonne of Hot Rolled Product) Canada plants

8 Example of Equipment Level Energy Intensity EcoTech Application of economically justifiable best practices

9 Use of Modeling Tools Detail performance analysis using PHAST Other - scale losses 4% Openings 3% Distribution of Energy Use A walking beam reheat furnace Flue gas loss 28% Wall losses 6% Water-cooling 8% Air leaks 7% Steel 44% Fixtures etc. 0% A tool such as Process Heating Assessment and Survey Tool (PHAST) can be used to analyze detail performance This information can be used to identify areas of energy inefficiencies and information on possible improvements. The tool allows correction for production rates, fuel quality, operational changes etc. The tool is available in Chinese language for use in China Energy Intensity: 1.37 GJ/ton at design condition 1.54 GJ/ton at 50% capacity E3M Inc. (October 19-20, 2011) 9

10 Effect of Capacity Utilization on EII Example: Analysis of a reheat furnace using PHAST WALKING BEAM FURNACE MM BTU/TON GJ or Tce per metric ton 25% 50% 75% 100% 125% TPH HEARTH COVERAGE 100% 50% HEATING TIME 89 minutes 89 minutes % of Total Heat Distribution WORK 86.43% 76.11% WALLS 1.85% 3.25% RAILS 4.78% 8.42% POSTS 2.25% 3.96% SLOTS 3.62% 6.37% MISC 1.07% 1.89% 100% 100% MMBtu/ton % UTILIZATION OF CAPACITY GJ/ton E3M Inc. (October 19-20, 2011) 10

11 ESPI Improvement Methodology Base lining and Benchmarking for Iron and Steel Industry The plant Plant energy systems Best practices applications New system Use of new technology Other means Base Lining Assessments Use of tools Current value of system specific EEI- ESPI Industry system benchmark Corrective Actions Comparison gap analysis Corrections for specific conditions (use of tools) E3M Inc. (October 19-20, 2011) 11

12 Use of Base Lining and Benchmarking Base lining and Benchmarks have been used to indicate comparative level of energy system performance. Base line data Benchmarks is expressed in commonly used ESPI such as energy intensity index (EEI). Benchmark must be corrected for several factors, discussed earlier, associated with system operation and design. It is necessary to develop and use system or process specific methods or tools to obtain corrected benchmark values for fair comparison. E3M Inc. (October 19-20, 2011) 12

13 Alternate Method Use of ESPI - EEI In this case energy intensity index (EII) is used as ESPI for a steel plant. EII is defined as EEI n i i i= 1 = 100 = 100 n n i= 1 P EI P EI i i, BP i= 1 E P EI i tot i, BP EII is calculated for a plant as well as individual processes. The best practice EII values are obtained from an International survey given in the document Energy Use in the Steel Industry published by International Iron and Steel Institute. Details given in Excel spreadsheets. The values are used to identify performance gap for the processes. E3M Inc. (October 19-20, 2011) 13

14 Suggested Steps Identify best practices (BPs) and select applicable BPs Analyze effect of the selected BPs and calculate new values of EEI. Effect of BP can be calculated by using tools such as PHAST, SSAT, PSAT etc. developed by U.S. Department of Energy or other calculation methods. Corrections for variable parameters and calculation of ESPI. The final result can be in terms of absolute value of reduction in energy use, CO2 reduction and reduction in energy cost. In some cases economic benefits include effect of productivity gains, quality improvement etc. if applicable. E3M Inc. (October 19-20, 2011) 14

15 Challenges Identification critical parameters. Data collection and validation Corrections for variable parameters and calculation of ESPI. Interpretation of corrected data and its translation in action items. Availability of reliable tools and methods to estimate savings associated with each corrective actions. Cost associated with the system implantation. Continuing activities and resource allocation to finetune the process equipment performance E3M Inc. (October 19-20, 2011) 15

16 谢谢 你 E3M Inc. (October 19-20, 2011) 16