The use of variable speed drives for cost-effective energy savings in South African mine cooling systems

2013 ◽  
Vol 111 ◽  
pp. 16-27 ◽  
Author(s):  
Gideon Edgar Du Plessis ◽  
Leon Liebenberg ◽  
Edward Henry Mathews
Author(s):  
ALPER GONEN

Energy is a basic need for industries around the world. In recent years, electrical power costs have risen considerably and this rise is likely to continue in the future. Meanwhile, the increasing cost of ventilating mines safely and efficiently is of vital importance. Ventilation on demand has the potential to optimize electrical consumption while maintaining the safety of mines. This paper investigates the energy efficiency enhancement through ventilation on demand in underground mines by installing variable speed drives on the auxiliary mine ventilation fans to provide variable airflow control. Variable speed drives are cost effective and manageable and require low maintenance. It has been estimated that a total electrical energy saving of 324,300 kW, or 53%, can be achieved in 1 year by using variable speed drives. Therefore, it is possible to reduce CO2 emissions by 155.6 tons per year with a simple payback period of 5 months 220 days.


Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2530 ◽  
Author(s):  
Luigi Cimorelli ◽  
Carmine Covelli ◽  
Bruno Molino ◽  
Domenico Pianese

Greenhouse gas emission is one of the main environmental issues of today, and energy savings in all industries contribute to reducing energy demand, implying, in turn, less carbon emissions into the atmosphere. In this framework, water pumping systems are one of the most energy-consuming activities. The optimal regulation of pumping systems with the use of variable speed drives is gaining the attention of designers and managing authorities. However, optimal management and operation of pumping systems is often performed, employing variable speed drives without considering if the energy savings are enough to justify their purchasing and installation costs. In this paper, the authors compare two optimal pump scheduling techniques, optimal regulation of constant speed pumps by an optimal ON/OFF sequence and optimal regulation with a variable speed pump. Much of the attention is devoted to the analysis of the costs involved in a hypothetical managing authority for the water distribution system in order to determine whether the savings in operating costs is enough to justify the employment of variable speed drives.


Author(s):  
Harold T. Snyder

The 3 C’s Cash - Control - and Coordination based on the use of variable speed drives in the Citrus Industry is covered in this paper. Proper use of variable speed drives results in more money (CASH) from Energy Savings, Reduced Maintenance cost, and Improved Efficiencies. By regulating the speed of pumps and conveyor belts, less problems from mismatched speeds occur (CONTROL). The timing of the material reaching the correct location through proper speeds of equipment means improved COORDINATION. The various types of variable speed drives and their manufacturers are discussed. The type of drives covered range from simple eddy current, with minimum control features, to electronic AC and DC drives with unlimited control functions. Paper published with permission.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4798
Author(s):  
Khan Rahmat Ullah ◽  
Marudhappan Thirugnanasambandam ◽  
Rahman Saidur ◽  
Kazi Akikur Rahman ◽  
Md. Riaz Kayser

Electric motors and boilers lead the industrial components which consume the largest portion of energy in an industry. This study explores the energy audit data of the condiment industry in India. The study mainly focuses on the estimation of the load factor, energy use, energy savings and annual bill savings with payback period of the electric motors of the plant. During the audit, it was found that there were several motors running under loaded conditions despite non-availability of variable speed drives installed in the plant. Therefore, variable speed drives are recommended to be installed to save energy by reducing the motors speed by up to 60%. According to the estimation, about 276 MWh, 551 MWh and 827 MWh electrical energy can be saved for 20%, 40% and 60% speed reduction of the motors using variable speed drives, respectively, where in most of the cases the payback period remains below 1 year. Furthermore, some suggestions are made to improve the poor power factor of running motors by using capacitor banks to save the reactive power. Besides, an estimation of energy saving is performed with a 2-ton capacity boiler. Since, there was no heat recovery system in the boiler; an air-preheater is suggested to be installed at the end of flue gas exhausting path of the boiler with the purpose of saving 68 tons of fuel per annum and having a payback period of 12 months. Moreover, a digital monitoring system, namely, “The Smart Joules” has been proposed to be installed in the plant aiming at saving about 3–5% of total energy per annum and having a payback period of 19 months. Finally, a summarization is made concluding in the fact that about 90 MWh energy and 95 tons of fuel can be saved (excluding motor energy savings) per annum by implementing proposed measures with a payback period of 15 months.


2015 ◽  
Vol 30 (4) ◽  
pp. 1288-1298
Author(s):  
Chien-Hsing Lee ◽  
Zhi-Wei Liu ◽  
Chien-Nan Chen ◽  
Ming-Yuan Cho ◽  
Foung-Tang Lin ◽  
...  

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