| Abstract |
The system is based on original, innovative technology for the development and utilization of shallow ground geothermal energy (heat) - the "Single Well System" technology. It has been invented and developed by Beijing Ever Source Science & Technology Development Co., Ltd to provide buildings with heating & cooling as well as with domestic hot water. Since this technique emerged in 2001, it has attracted the attention of users and government agencies in China. For the Single Well System, generally, a borehole of about 70-80m depth and with a diameter of 0.5 m is drilled. The prerequisite for geological site condition is to have a shallow aquifer with hydraulic conductivity of 10-3 m/sec or higher. Groundwater with about 12-15?C is pumped from the well and at a rate of 100 m3/h passes through heat exchangers to release heat to the heat pump. The heat pump provides water with temperature of about 50-55?C to supply fan coilers for space heating whereas the released well water temperature is lowered down to 10?C. This water is then injected into the same well where a special soil heat exchanger takes heat from the surrounding sand and gravel (patent holder: Beijing Ever Source Science & Technology Development Co., Ltd.). By these means, the water temperature returns back to its original temperature of 15?C. The thermal power of a single well is around 0.6 MW. In summertime, "direct cooling" (i.e. with heat pump switched off) is directly provided by the groundwater after heat exchange. The paper describes the system design and its energy-saving and environmental protection effects by an operating installation in the Beijing area. Further, successfully operating systems in various parts of China are presented, which encompass a wide range of building types and purposes: residential building (single family houses and apartments), office building, hotel, hospital, shopping center, school, waterscape pool (the Chinese National Theatre). The system is also foreseen to serve buildings of the 2008 "Green" Olympics in Beijing. As of August 2004, over 180 such systems are in operation, with a total area of 2'500'000 m2. The saving of fossil fuel like coal is equivalent to avoiding the emission of 260'000 tons of CO2, 2'200 tons of SO2 and 1'600 tons of NOx. In comparison with direct electrical heating it can reduce power consumption by up to 3/4. The system is now ready for worldwide implementation. |