Research On ATES Key-Technology In Shanghai

As we know, ATES was invented and applied at large scale, in Shanghai during1960s, which influenced outside world. On western side, most research work andexperience setup was accomplished in1970s. Nevertheless, none of those countriesseemed to have further development on commercial application on ATES during late1990s, the Netherlands was an exception. From the history of world ATESdevelopment, we know a lot of factors could influence the sustainability applicationof ATES, such as any suitable aquifer, legal issue and government policy, energyconcept, economic feasibility etc. But, the most important issue is whether thegroundwater could be fully re-inject into aquifer and its impact on localgeo-environment, which is the key to application of ATES.This paper concluded the lesson of ATES development in Shanghai, theexperience from Dutch successful story. The new techniques had been suggested,which included well design, drilling technology, well development and groundwatercircuit construction. Regarding well design, more attention should be focus on itsinfluence on environment and sand and silt content. To ensure the quality of the well,the air-lift reverse circulation drilling method would be used. In order to preventclogging due to corrosion, the UPVC well casing and screen would be used. The slotsize of screen fit with the grain size of gravel and aquifer. The pressure injectionmethod would be adopted to prevent leakage of air from outside. With these methods,the quality and lifespan of well would be improved significantly, which could be asolution for groundwater injection problem nowadays.Furthermore, the analysis had been done on what so call “shallow geothermal”,the terminology had been popular used by ground source heat pump system. Theconclusion was there was almost no “shallow geothermal”, and the role of shallowpart of earth, as matter of fact, was underground thermal energy storage (UTES)which was used in passive way. Once UTES was not effective, the energy efficiency of system could be reduced. The clarification of this concept could help HVACengineer to prevent to failure of the system, and preserve eco-environment ofsubsurface.In order to have more accurate design of ATES system, well group optimization,prediction of system energy efficiency, and its impact on environment, themathematics mode of ATES had been established with numerical solution frompopular hydrology software of MODFLOW. The results of simulation were promising,with some remarkable conclusions:1) The wells arrangements did have hydraulicimpact, and the proper arrangement of wells could significantly reduce these impact;2) The different arrange of well seemed not much influence on the thermal influenceregion, yet we didn’t know for its energy efficiency which should be further study;3)The subsurface was influenced by heat and cold balance of ATES system. Theunbalance system could results either ever increasing the cold or warm influenceregion of subsurface, which should be avoided also from energy efficiency point ofview.