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Mar 12 2011 by TNguyen

Mar 11 2011 by richard__perkins@hotmail.com

Mar 2 2011 by chrisand

Feb 27 2011 by prospero

Thanks. This is a bit more information. Thermofluidics is developing NIFTE to remove parasitic loads from existing technologies and to integrate different technologies to exploit synergies between them. 1. Our current development priority is water circulation in domestic solar thermal systems with forced circulation. The NIFTE interfaces the solar collectors directly with the circulated water to remove the parasitic load of the existing circulator pump from the grid. We have proven the potential for 1000L/hr flow rate and 9m stalling head and commissioned beta prototypes for field trials. Electric circulators are responsible for an estimated 10% of domestic electricity consumption in the EU (EU SAVE II project findings). NIFTE is completely passive, starting when a sufficient temperature difference is present between the collector and the hot water storage tank, and stopping when this difference is too small. 2. Our five Beta prototypes may be applicable as demonstrators in other home applications: Swimming pool filtration pumps using boiler waste heat or solar thermal; circulation pumps in absorption cycle air-conditioning and thermally powered ground source heat pumps; and coolant circulation and gas compression in PEM fuel cell systems using waste heat. 3. As a circulator, the NIFTE can facilitate the integration of solar thermal or domestic CHP with ground source heat reservoirs, to improve vastly the global performance of each component of the system. In high latitude regions (such as the UK), we estimate that around 70% of solar radiation incident on solar thermal collectors is wasted, as heat supply far exceeds demand during summer months, when insolation is greatest, as systems are sized in order that useful heat may be available in winter months. Forcing collectors into stagnation under high insolation conditions imposes difficult design requirements which force further performance compromises and increase cost and installation difficulty. Meanwhile, ground source heat pumps often perform less well than projected, as boreholes and trenches are undersized for cost and access reasons, so that heat must be raised from thermal reservoirs at temperatures significantly below ambient in the late winter/early spring. Even an oversized reservoir requires that heat be raised from as little as 5 to 10 degrees C. However, as a circulation pump, NIFTE can store solar heat in the ground during summer months, thereby making use of the 70% of the radiative heat load currently wasted, and relaxing the design requirements of the collectors. Simultaneously, the same indoor temperature can be maintained throughout the year with significantly lower heatload placed on the heat pump. 4. In the longer term, NIFTE may be able to replace electric heat-pumps entirely, as a key enabling component in an absorption heat pump/refrigeration cycle, or as a Duplex heat-pump (two NIFTE devices operating back-to-back). Apart from the significant capital cost and maintenance cost savings implied, this is an ideal means of combining the benefits of solar thermal, micro-CHP and ground source heat pumps into the same box, but without the difficulty and regulatory difficulties of a grid connection. 5. This offers a means of completely circumventing the unpredictable supply/demand curves of CHP/heat pump devices “by the back door”, without requiring changes to grid infrastructure that are currently being forced (e.g. there have been a number of blackouts in central London reportedly due to new demand from heat pumps).