ENERGY AUDIT OF HOT ROLLING MILL IN JSL STAINLESS LTD.HISAR By Manoj Bhardwaj,Electrical
Abstract
JSL Stainless Limited is one of the leading and professionally managed steel industry of India. This company was set up in 1970 by the steel visionary Mr. O.P. Jindal, has grown up in a multi unit steel plant in Hisar, Haryana. JSL Stainless Ltd. is a ISO: 9001 & ISO: 14001 company is the flagship company of the Jindal Organization. Now, at Hisar, JSL Stainless Ltd. has India's only composite stainless steel plant for the manufacture of Stainless Steel Slabs, Blooms, Hot rolled and Cold Rolled Coils, 60% of which are exported worldwide. This company in so many units out of which steckel unit of hot rolling mill is selected for energy audit, as it is the main component of JSL Stainless Ltd., Hisar. All of the other units dependent upon it. It is obvious that energy audit is the key to a systematic approach for decision-making in the area of energy management. In general, Energy Audit is the translation of conservation ideas into realities, by lending technically feasible solutions with economic and other organizational considerations within a specified time frame. First of all in this energy audit work essential or preliminary data is gathered. This is also termed as preliminary audit which uses only available data and is completed with limited diagnostic instruments. This collection of data relies on all the relevant written, oral visual information that can lead to a quick diagnosis of the plant energy situation. This also focuses on the identification of obvious sources of energy wastage's. Then with the analysis of this collected data along with the use of sophisticated instruments such as flow meter, pressure gauge, power analyzer etc. The typical out put of this energy audit is a set of recommendations as per the estimate of the scope for saving, identified the most likely and easiest area for attention and also with some proposals for immediate improvement especially with no/low/heavy cost action. SUMMARY OF PROPOSALS WITH CONCLUSION: 1. Replacement of induction motors with energy efficient motors whose working hours are 12 hrs or above per day with 15 HP and higher capacity motors with attractive pay back period. 2. Installation of a Star-Delta-Star Converter with built in microprocessor based relay for those induction motors whose load varies below & above 40%. 3. Because of good performance of motors at constant voltage it is proposed to keep constant voltage at motor terminal as voltage fluctuations are much in steel industry. 4. To reduce cable losses use of another same size cable in parallel, replacement the existing cable with large size cable or 30-40% power factor correction equipment is proposed to connect at load terminal. 5. Replacement of all filament lamps is proposed with LED energy efficient lamp in all control panels of motors. 6. Replacement of specific conventional transformer such as 1.6 KVA, 2 KVA, 2.5 KVA, 3 KVA & 4 KVA are proposed with energy efficient transformer to reduce losses. Re-scheduling of distribution transformer is also proposed to reduce losses by load sharing. An indoor conventional type distribution transformer is also proposed to replace with a cast resin dry type transformer. 7. A separate lightening feeder is also proposed for main lightening as well as street lightening and also proposed to operate all lightening circuit at 215 Volt by using servo voltage stabilizer. 8. A neutral compensator is also proposed for uneven distribution of load as there is different phase to neutral voltage and heavy return current flow in neutral line. 9. Selection of pump should be as per requirement of flow and head as well as it should be based on BEP curve so that the energy can be saved. Identified pumps should be controlled through variable frequency drive. To save energy the pumps do require periodic maintenance. 10. There must be provision of energy management system (EMS) in the organization so that there can be increase in productivity and desired target can be achieved with system reliability and improvement in energy utilization.
