A consortium composed of the Siemens Industrial Solutions and Services Group (I&S) and Siemag GmbH, Netphen, has received an order from SDIC Xinji Energy Co. Ltd. to supply three winding machines for two coal mines in Anhui, a province in China. The Siemens scope of supply comprises the winding motors, including converters, as well as the power, automation and safety systems. The total order value is around 14 million euros.
Xinji Energy is a leading coal producer with mines in the east Chinese province of Anhui. At the present time, the company is building two new shaft installations in Banji and Kouzidong. The Banji mine, which will be supplied with a new winding machine, will have a winding capacity of three million metric tons per year at the end of 2007. The installation in Kouzidong is to produce around five million metric tons of coal per year with the help of two new winding machines.
The three machines of the identical winding installations are four-rope friction wheel ground-mounted machines with a diameter of 4.8 meters. Siemens is supplying the synchronous motors, each with an output of 4.7 megawatts, as well as the associated 12-pulse cyclo-converters of the type Simovert D. Motors and converters are air-cooled.
The drives will be controlled by means of an FM458 Simatic application module. For safety reasons, the controller has two channels. The signals of these two channels will be compared with each other continuously. A discrepancy will trigger a safety circuit which will immediately stop the drives and apply the safety brakes. A visualization system with an operator console will be available for operator control and monitoring. The scope of supply also includes high-voltage transformers, the low-voltage switchgear and motor blowers. The winding machines have an emergency operating mode, which means that, even if faults occur in a converter or transformer, production can continue at half speed but with the full load of 32 metric tons. Siemens is also responsible for commissioning the equipment on site whereas Siemag GmbH is responsible for the mechanical components.
The main factor which tipped the balance in favor of Siemens as the supplier was the good experience SDIC Xinji Energy had gained with Siemens when the latter installed winding machines in the Liuzhuang mine in 2005. Another important factor was the range of advantages provided by the cyclo-converter drive systems, especially at high torques at a standstill as is the case with winding machines in “rope shortening” mode.