This makes them economically feasible in application areas where pumps are not currently viable. NIFTEs are capable of pumping many different fluids, from shear sensitive biological cultures to viscous and chemically, or mechanically abrasive media. They have a gentle pumping action, and operate in almost total silence. NIFTEs can be tuned during operation to suit a range of different pumping head and flow requirements, and available power sources.
Circulation pumps
Circulation pumps are used to circulate hot water from central heating boilers around radiators and hot water tanks. According to a leading manufacturer, "there are over 120 million circulators in the EU consuming 57 TWh, which equals twice the consumption of washing machines in the EU". This is equivalent to the output of approximately six UK nuclear power stations.
Domestic wall-hung, gas-fired, condensing boiler
with circulator pump in bottom right-hand corner
By using waste heat from exhaust/flue gases in fossil fuel fired heating systems, or by tapping some heat from the combustion chamber, NIFTE devices can perform the role of the circulator, dumping their waste heat in radiators, or the cold intake air from outside. Either way, the net energy efficiency of the system is increased, and the need for electricity is circumvented.
Schematic of the NIFTE circulator pump
Circulators based on NIFTE devices are particularly applicable in stand-alone solar systems, in which the sun's energy is used to heat water for direct use or for central heating. Currently, solar thermal systems either require a hot water cylinder to be located above, and close to them, or they require an electric circulator pump. NIFTE devices can circulate water around solar collectors using some of the heat harvested from the collectors themselves.
Apart from the huge energy savings that NIFTEs can bring to hot water circulating systems, they can make hydronic heating independent of a mains electricity supply. This could prevent thousands of deaths for hypothermia each year.
We have written a short technical brief (Microsoft Word .doc format) that contains detailed information about the NIFTE circulator pump, and explains carefully how the NIFTE pump would work this application, our current progress and outlines the key development areas that we are currently working on. We have also prepared a shorter 2-page pamphlet (Adobe Portable Document Format .pdf format), which provides some information about Thermofluidics, the NIFTE technology and the solar application. In addition, we have compiled a short comparison (Microsoft Word .doc format) between the NIFTE and a conventional electric pump in this application.
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Low cost solar powered pumps
Solar powered pumps for water supply, sanitation, and irrigation tend to be expensive, fault prone and unreliable, particularly on smaller scales. The far majority of existing solar pumping systems are based on photovoltaic solar cells, which convert sunlight to electricity before it is converted to hydraulic work by an electric pump. Photovoltaic cells remain expensive. In addition, they only operate efficiently over a small range of voltages. As the level of sunlight which falls upon them increases or decreases, the current which they can deliver also increases or decreases. In order to operate efficiently, electricity must always be taken from them with a maximum product of voltage times current. This means that they can only drive the majority of electric pumps efficiently under one pre-determined level of sunlight. Some photovoltaic pumping systems use power modulating circuitry known as 'maximum power point trackers', to match the photovoltaic cells to the pump under a range of conditions. However, these add extra losses to the system, they are fault prone, and they are expensive.
A solar roof that is part of a photovoltaic pumping installation
Solar powered pumps based on NIFTE devices can use off-the-shelf solar thermal (hot water) collectors to convert solar radiation into usable heat. Solar thermal collectors are much cheaper than photovoltaic solar cells. Furthermore, pumps based on NIFTEs can use the water which they pump as a source of cooling water. In this application, they could undercut the cost of photovoltaic systems by up to 5 times.
Schematic of the NIFTE solar pump
Unlike photovoltaic pumping systems, solar pumps based on NIFTEs do not require power point tracking to operate at peak performance under different sunlight levels. This is because solar thermal collectors can operate efficiently over a large range of temperatures (c.f. photovoltaic cells which only operate efficiently over a small range of voltages). NIFTEs can be pre-tuned to match a given collector to a given pumping load, so that as the level of sunlight changes, the collector automatically changes to a new optimum collecting temperature, which is also the new optimum heat input temperature to the NIFTE, pumping at the new peak flow rate.
We have written a technical brief (Microsoft Word .doc format) that contains detailed information about the NIFTE solar pump, and explains carefully how the NIFTE pump would work this application, our current progress and outlines the key development areas that we are currently working on. We have also prepared a shorter 2-page pamphlet (Adobe Portable Document Format .pdf format), which provides some information about Thermofluidics, the NIFTE technology and the solar application.
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Thermally powered pressure boosters
The need to increase the pressure of a fluid at the same time as heating it occurs in many cases other than in central heating and hot water systems. Common examples include steam cleaners, espresso machines and power showers, amongst many others. In industry, there are countless examples of cases in which this need occurs.
NIFTE devices are particularly well suited to these sorts of applications, because they are applications in which a high grade energy source (e.g. electricity) is already being used for pumping and heating at the same time. Therefore, a NIFTE device can replace the ensemble of pump plus heater, pumping a fluid and dumping its waste heat in the same fluid, with much greater reliability and at lower cost. Furthermore, the ratio of heating power to pumping power can be changed in real time, simply by adjusting the NIFTE's feedback valve to select a more efficient (high pumping power, low heating power) or less efficient (low pumping power, high heating power) operating regime.
Absorption refrigerators
Absorption refrigeration cycles (ammonia-water, lithium bromide - hydrogen - water and others) are a thermally powered alternative to vapour compression refrigeration cycles. Unlike vapour compression cycles, absorption cycles do not rely on mechanical compressors, which are costly and require electricity to operate.
Absorption refrigerators have been in widespread use for many years. In fact, almost all early gas powered refrigerators were based on an absorption cycle. Nowadays, they are only commonly used in applications where electricity is scarce or supply is unreliable, such as propane powered fridges in caravans and mobile homes.
Vapour-compression cycles replaced absorption cycles in terrestrial refrigeration and air conditioning, as electricity (rather than gas) became the standard means of energy distribution.
There is renewed interest in absorption cycles for solar powered, and other thermally powered refrigeration and air conditioning systems, in the quest for lower fossil fuel consumption, and 'off grid' refrigeration, particularly in developing countries.
Some absorption cycles operate at two very different pressures, and employ a powerful pump to move liquid refrigerant from the low to the high pressure region. Although this pump is usually electric, it requires much less power than a compressor in a vapour-compression refrigeration cycle. Other absorption cycles operate intermittently, or at a single pressure, and only require a pump to circulate refrigerant.
In either case, NIFTE devices are particularly well suited to perform these tasks as they are also thermally powered, cheap to produce and highly reliable.
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Micro-electronics scale embedded pumps
The fact that NIFTEs have no moving parts (other than two non-return valves for uni-directional flow applications) means that they can be scaled up or down relatively easily. Scaling mechanical devices down to microchip sizes poses all sorts of problems. Manufacturing minuscule bearings, cranks, and tolerance seals is extremely difficult. However, NIFTEs comprise only tubes and restrictions with low manufacturing tolerances and can be manufactured on minute scales relatively easily.
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Sensitive or abrasive media
NIFTE devices have no moving parts other than two non-return valves which are required for uni-directional pumping applications. However, for heating and mixing applications, NIFTEs do not require moving parts at all. This makes them well suited to heating and/or mixing both sensitive and abrasive media.
There are various non-return valve designs which can be used to have a minimal effect on a shear-sensitive fluid medium, and there are others, such as diaphragm valves, which are very resistant to abrasion. From the scale of laboratory pumps and mixers to large scale concrete and slurry pumps, NIFTE devices have the potential to reduce costs and improve lifetime and reliability.
