Problems facing the development of heavy industry in modern society
Energy is a significant cost factor for heavy industry. According to data from the German Federal Statistical Office in 2008, energy consumption accounts for a high proportion of the total life-cycle cost across various industries in Germany. For example, energy consumption accounts for 57% in the aluminum industry, 47% in cement, 36% in steel, 29% in pulp and paper, and 27% in basic chemicals. For electrical drive systems, energy consumption accounts for at least 80% of the life-cycle cost. Therefore, many countries have introduced policies and regulations related to energy and environmental protection to encourage heavy industrial enterprises to actively carry out energy-saving industrial transformation.
The overall goals of my country's 12th Five-Year Plan are as follows:
In response to the achievements of the 11th Five-Year Plan, my country has imposed stricter requirements on energy consumption in various industrial sectors during the 12th Five-Year Plan, which has increased the pressure on each sector to varying degrees.
By 2015, China's energy consumption per 10,000 yuan of GDP had decreased to 0.869 tons of standard coal equivalent (calculated at 2005 prices), a 16% decrease from 1.034 tons of standard coal equivalent in 2010 (and a 32% decrease from 1.276 tons of standard coal equivalent in 2005). During the 12th Five-Year Plan period, energy savings of 670 million tons of standard coal equivalent were achieved. In 2015, total emissions of chemical oxygen demand (COD) and sulfur dioxide (SO2) were controlled at 23.476 million tons and 20.864 million tons respectively, representing an 8% reduction from 25.517 million tons and 22.678 million tons in 2010, with newly added reduction capacities of 6.01 million tons and 6.54 million tons respectively. Total emissions of ammonia nitrogen and nitrogen oxides were controlled at 2.38 million tons and 20.462 million tons respectively, representing a 10% reduction from 2.644 million tons and 22.736 million tons in 2010, with newly added reduction capacities of 690,000 tons and 7.94 million tons respectively.
Siemens – Industrial Analysis and Energy Saving Experts
Based on the above requirements, various enterprises have joined the ranks of industrial energy-saving renovations in order to save energy costs and enhance their corporate image as quickly as possible. Based on this huge demand, Siemens, with its years of experience, rigorous energy management processes, comprehensive product line, and flexible product portfolio, provides highly efficient energy-saving and efficiency-enhancing solutions for industrial users. Through the Energy Performance Contracting (EPC) model, Siemens saves enterprises significant funds and promotes their increasing competitiveness.
How to achieve good energy-saving results?
Siemens believes that motors (such as drives or pumps) often account for two-thirds of total energy consumption in the industrial sector. Siemens' energy-efficient motors and intelligent control systems can reduce total energy consumption by up to 60%. Energy conservation and emission reduction measures alone can achieve a cost recovery target within two years.
Siemens SINAMICS intelligent frequency converters help businesses achieve intelligent energy-saving management. By leveraging SINAMICS intelligent frequency converters, various energy-saving potentials can be fully realized, effectively reducing energy consumption. Using these converters, energy consumption can be effectively controlled by adjusting motor speed according to specific application needs. When used with drive units such as fans, pumps, and compressors, energy savings of up to 70% can be achieved. In addition, SINAMICS frequency converters also feature energy recovery capabilities, making them the preferred choice for high-efficiency drive units, whether in the low-voltage or high-voltage product series.
Classic Energy-Saving Renovation Case Study 1: Energy-Saving Renovation in the Steel Industry
As one of the most energy-intensive industries, the steel sector's energy consumption is a major concern. For large steel companies like Taiyuan Iron & Steel Plant, whose stainless steel products range from high-tech equipment to everyday consumer goods, output and energy consumption are enormous. Therefore, industrial energy-saving retrofitting is a significant challenge for them. However, for Siemens, this challenging situation presents an even greater challenge! Siemens' energy management methodology, based on a three-step process, enabled Taiyuan Iron & Steel Plant to quickly and accurately implement frequency conversion energy-saving retrofitting for its large-scale fan equipment.
The first step was to analyze the No. 3 450m² sintering machine, which does not use variable frequency speed control, to identify the energy-saving potential of Taiyuan Iron & Steel Group.
The second step is to assess the costs of the workshop and system throughout their entire lifecycle, and to calculate the energy-saving potential and cost-effectiveness of feasible measures for specific applications.
The third step is to take targeted measures to turn energy-saving potential into reality. Approximately two-thirds of industrial energy is consumed by the drive system, and reducing the energy consumption of the entire drive system by 40-50% is highly feasible.
The No. 4 sintering machine of Taiyuan Iron & Steel Group, with an area of over 600m², uses two sets of Siemens Robicon high-voltage frequency converters and high-voltage motors. One large frequency converter can save 5,000 kWh of electricity per hour, and two large frequency converters can save 240,000 kWh per day. Calculated at a self-supplied electricity price of 0.4 yuan/kWh, this translates to annual electricity savings of over 30 million yuan, recovering the equipment cost in 18 months, and achieving an energy saving rate of up to 40%. This transforms the initial equipment investment into a successful strategic technological innovation.
In building itself into a resource-saving enterprise, Taiyuan Iron & Steel (TISCO) has ensured year-on-year output growth while energy consumption has decreased annually through the use of Siemens variable frequency drive solutions, fully integrated automation, and advanced steelmaking processes from Voestalpine. TISCO General Manager Gao Xiangming stated, “Compared to 2005, in 2011, TISCO’s comprehensive energy consumption per ton of steel decreased by 22.9%; fresh water consumption per ton of steel decreased by 91%; and the annual recovery of secondary energy accounted for more than 45% of total energy consumption, reaching an industry-leading level.”
Classic Energy-Saving Renovation Case Study 2 – Energy-Saving Renovation in the Cement Industry:
Siemens' first energy performance contracting project was an industrial energy-saving renovation for Inner Mongolia Wulan Cement. Siemens combined advanced business models and technologies to help its client, the Inner Mongolia Wulan Cement plant, save energy and reduce emissions. The project involved upgrading 16 kiln head and kiln tail fans across three production lines using 16 Siemens MasterDrive frequency converters, with a total power of 1312kW, and was completed in 2007. Measurements showed significant energy savings, with an annual electricity saving of 3.68 million kWh compared to before the renovation, representing an energy efficiency of over 35%. This energy saving of 3.68 million kWh is equivalent to approximately 1269 tons of standard coal equivalent per year, saving the client 1.84 million yuan in electricity costs annually based on local industrial electricity prices.
In the cement industry, the energy consumption of fans is increasing, accounting for approximately 30% to 40% of the total plant electricity consumption. To save on fan power consumption, a variable frequency drive (VFD) system is needed. By adjusting the motor speed, the air volume and pressure required for different fan operating conditions can be met, thus achieving energy savings. The project between Siemens and Shaanxi Qinling Cement Group is an energy performance contracting project. Its initial investment will be returned through energy-saving benefits. The 1250kW harmonic-free VFD provided by Siemens is applied to the high-temperature fan at the kiln tail, achieving an energy saving rate of over 28% and annual energy savings of 1.4 million yuan.
Professional value-added services enabled Taiwan Cement to achieve an average energy saving rate of over 22%. Siemens upgraded the high-voltage frequency converters for the large fans in Taiwan Cement's cement clinker production line by installing, commissioning, and using 24 sets of Siemens-RoboCon harmonic-free high-voltage frequency converters, increasing the total power output by over 60 MW. This resulted in an average energy saving rate of over 22% for Taiwan Cement, allowing the client to fully recover their initial investment in less than 14 months. Simultaneously, the unit energy cost was reduced by 3%, enhancing the client's market competitiveness and bringing significant added value.
Advanced technology can more effectively unlock greater energy-saving potential and truly achieve "saving every kilowatt-hour of electricity during use!" Siemens' world-class portfolio of products, systems, and solutions can continuously improve energy efficiency according to established goals, creating a new prospect for continuously enhancing competitive advantage.
For more information on energy conservation and efficiency, please visit the Siemens Energy Conservation and Efficiency website: http://www.industry.siemens.com.cn/topics/cn/zh/energy-efficient-production/Pages/Default.aspx
