The quantity and composition of the ash content of straw poses technical challenges to its thermal conversion and have been widely reported to cause severe ash sintering and bed agglomeration during fluidised bed gasification. Literature indicates that a combination of reactor design and bed material measures is required to avoid defluidisation at temperatures above 800 °C. Using scanning electron microscopy and energy dispersive X-ray spectroscopy this study investigated the initial agglomeration of a mullite bed during the

Despite an increasing use world-wide of geothermal energy foundations there is a lack of published guidelines and results from thermal response testing of such installations. In this paper the results from thermal response, thermal recovery and laboratory thermal testing performed at two sites in Ireland are presented. Some practical issues concerned with use of thermal response testing rigs, designed for use with deep boreholes, on relatively short piles are discussed and addressed. Given the relatively short geothermally active depth of the energy foundations tested and due to the fact that the UCD thermal response testing rig has been designed primarily for testing on medium and deep geothermal boreholes, shorter thermal response test durations than are normally

Water extracted from beneath the Docklands shows that significant water chemistry issues exist.Laboratory and field tests confirm that optimal concentration levels of several water chemistry characteristics are significantly exceeded; leading to the conclusion that open loop exploitation in the area may not be suitable. In addition, settlement induced by pumping of water could potentially lead to a consolidation settlement in excess of 30 mm due primarily to the existence of highly compressible alluvium. Notation: strain

A thermal response test (TRT) is a controlled insitu test during which a known quantity of heat energy is injected into a closed loop heat-exchanger pipe while the heat dissipation rate into the surrounding ground is monitored. Results from a test can be interpreted to determine a number of ground thermal parameters with are vital design requirements for any medium to large scale ground source energy system. This paper describes the design and construction of a low cost TRT rig and compares the results obtained from a test using the constructed rig and a commercially built rig in order to evaluate the accuracy of the constructed equipment. The TRT rig is designed in accordance with the following principles: keep construction costs low, improve the cost-efficiency of TRT testing by incorporating remote data transmission capability and ensure attainment of sufficient accuracy to satisfy the design requirements of ground source energy systems. Analysis of data collected by the TRT rigs result in a calculated thermal conductivity of 1.9 W/mK in both cases. This value falls within the range expected for the tested geological formation and confirms the accuracy of both test rigs.

Publication informationInternational Journal of Low-Carbon Technologies, 9 (4): 284-295Publisher OUP Item record/more information http://hdl.handle.net/10197/3946Publisher's version (DOI) http://dx.doi.org/10.1093/ijlct/cts077Title: A preliminary study of the effect of groundwater flow on the thermal front created by borehole heat