Shaanxi Qinling Cement (Group) Co., Ltd. (hereinafter referred to as "Qinling Cement") is one of the 60 key cement enterprises under state construction (Figure 5.4). The company has newly built two dry rotary kiln production lines with an annual output of 2,500 tons of cement clinker, one with an annual output of 5,000 tons of cement clinker, one with an annual output of 200× 104t cement grinding production line and one with an annual output of 300× 104t special cement production line.
Figure 5.4 Shaanxi Qinling Cement (Group) Co., Ltd.
Cement industry is an important basic industry of national economic construction, and it is also a big energy consumer. Facing the arduous task of saving energy and reducing consumption, changing backward production mode and improving technology and equipment. Today, with the requirement of environmental protection becoming the mainstream consciousness of society, cement enterprises will face greater pressure of energy saving. As a production enterprise with a history of more than half a century, Qinling Cement is the primary problem. This provides a stage for the implementation of contract energy management.
In 2007, the high-temperature fan at the kiln end of the new dry cement production line of Qinling Cement No.6 kiln was transformed into frequency conversion and energy saving. This is a technical transformation project jointly implemented by Xi 'an Energy Saving Service Company Qinling Cement and Siemens Industrial Automation and Drive Technology Group. It is the first energy-saving technical transformation project in the cement industry in Shaanxi Province and even in the northwest.
During the energy-saving transformation of high-temperature fan at kiln tail, Qinling Cement cooperated with a third-party energy-saving service company in Xi 'an to purchase a PH-6 Siemens-Robinson perfect harmonic-free high-voltage inverter, which was leased to Qinling Cement to start and adjust the operation of high-temperature fan motor. By comparing the electrical and mechanical consumption of the high-temperature fan at the kiln end before and after the implementation of the project, the energy-saving efficiency and benefit are calculated by rigorous methods, and part of the electricity saved is given to the energy-saving service company, and the rest is the income of Qinling Cement. After the contract energy management project is completed, the ownership of the frequency conversion equipment belongs to Qinling Cement for free. In fact, energy-saving service companies have recovered their investment costs in a relatively short time.
Fan frequency conversion energy-saving project belongs to the circular economy development project encouraged and supported by the state. Qinling cement high-temperature fan frequency conversion energy-saving renovation project, energy-saving service company funded the purchase of equipment, enterprises only invested 300,000 yuan in the construction of frequency converter room and laying of high and low voltage cables. After the transformation and operation, it is estimated that the annual energy saving will exceed170×104 kw h, and the electricity fee will be converted to more than 800,000 yuan, with the energy saving rate exceeding 25% promised by the original energy saving service company, and the energy saving effect is quite obvious.
The successful implementation of contract energy management has brought considerable energy-saving benefits for Qinling Cement, stable profit returns for partners, good social benefits for local governments and a win-win situation.