Efficiency Meets Innovation

Tovenvor Tabers

Introduction

Cooling is dominated by refrigeration technologies wherein various refrigerant gases are allowed to change phase from liquid to gaseous (absorbing the latent heat of vaporisation from the air) thereby removing thermal energy from the air to be cooled and then the refrigerant is recondensed with the latent heat of condensation expelled into an area that does not need cooling. In the case of air-conditioning, this is normally outside and in the case of a refrigerator, it is normally at the rear of the device or base. This process has hitherto been deemed the most energy efficient method of cooling.

It is estimated that by 2050 energy demand for space cooling will more than triple (Ref: https://www.iea.org/reports/the-future-of-cooling), it is therefore estimated that more than 30% of all global electricity power consumption will be related to cooling in its various forms from data centres to domestic cooling especially with increased global temperatures. This also means that emissions from cooling are predicted to account for more than 10 per cent of global emissions in 2050 (Ref: https://www.unep.org/news-and-stories/press-release/key-measures-could-slash-predicted-2050-emissions-cooling-sector ).

The process has been optimised but is still fundamentally flawed as the heat is simply removed and rejected. Moreover, refrigerants have to be property disposed of and have historically been responsible for Ozone layer depletion. Tovenvor Tabers or TT, is a new type of cooling system which does not use refrigerants and, also converts some of the rejected heat into work (electricity). Thermal energy can be used to create electricity and this is the basis of most steam and gas turbines worldwide. The innovation utilises the rejected thermal heat to create electricity which in turn reduces the net power consumption for cooling. There is no refrigerant used and the innovation couples several established thermodynamic and fluid mechanic principles.

The innovation will provide cooling to the most remote places on earth without the need to power from central power grids. The technology is not a perpetual energy machine but rather uses the rejected heat to power small microgenerators contained in a heat recovery loop. The amount of recovered energy exceeds the power by the fans to pull in air from the area requiring cooling. The consequences of the innovation proving to be correct are profound, not only from a perspective of climate change but for provision of refrigeration and cooling to developing countries that have a poor infrastructure. Vaccines, food safety, heat exposure, the list is huge. It sounds too good to be true. Its real. Read on.

The Innovation

The innovation is a closed loop cooling system which is created by creating a looped venturi vacuum system with inline co-axial fans to create air flow inside the loop and create vacuum points in the loop. The venturi vacuum loop is specially designed with inlet air vents to pull in air via a physical process known as ‘entrainment’ into the looped device. Entrainment is seen in the Dyson bladeless fans and its also used in turboprop engines in modern jet engines. Air is pulled into the looped venturi vacuum and rapidly compressed. The compressed air is released into a Vortex Tube (Ranque Hilsch tube) which separates the air flow into hot and cold streams. Vortex tubes are widely used for spot cooling and have have no mechanical parts. A vortex tube can take air at room temperature and cool down by anything from 4 degrees to 40 degrees lower. The tube splits incoming air into hot and cold air streams. The cold stream is used to push back into the area/device that needs cooling and the energy in the air is concentrated in the hot air stream.

The hot air stream contains hot energetic air which is connected to a looped microgenerator system called TABERS (torodial asymmetric biconical energy recovery system). The hot air turns the microgenerator turbines to create electricity. In doing so, the thermal energy is converted to work and the gas cools. The cooler gas is pulled out of TABERS by the venturi vacuum inlets which pull the air back into looped venturi vacuum wherein it mixes with the incoming air and is pushed back into the vortex tube after being compressed.

The innovation pulls out air from the area needing cooling, splits the air into hot and cold air streams. The cold air is returned to area requiring cooling and the hot air stream is used to recover energy. As cold air replaces the warm air, eventually the air temperature drops to the desired temperature at which point the fans stop.

How much energy do the fans use to pull in the air from the area to be cooled. In the POC, we are using a fixed volume container. A fridge, made of triple walled recycled polycarbonate.
How much energy is recovered from the rejected heat. Air has thermal energy of 1KJ/Kg/K. Food and drinks in a fridge also have thermal energy (hence the need cooling). This provides the energy for the energy recovery system.
A 1m3 fridge would at 25oC would contain 23KJ of energy if it were cooled to 2 degrees Celsius from 25oC. The fans required to pull in the 1Kg of air and cool it to 2oC are ducted (so more efficient than unducted fans) and the fans are in a loop. When in a loop, each fan reduces the static operating power of another fan in the loop. Thus reducing the overall energy required to move the air. The volume of air moved is the sum of the number of fans in the loop.

If the air is cooled to 2oC, then the hot stream must under conservation of energy contain 21KJ (less system losses). If the energy recovery system has a conversion efficiency of 50%, then 10.5KJ will be recovered to power the fans pulling in the air. As the energy recovery loop is subject to low pressure from the venturi vacuum inlet, turbine efficiency will be high.
The net power utilised will be the power consumed less the power recovered from the concentrated thermal energy in the hot stream. In our opinion, the energy recovered from the concentrated thermal energy from the hot stream will slightly exceed the power required to pull in the air from the area requiring cooling.
A battery will be required to start the fans and this could be recharged from the energy recovery system.
It is NOT a perpetual energy recovery system as the energy source is the thermal energy is air which is 1KJ/Kg/K. The thermal energy is air is concentrated by the vortex tube and this is used to power microturbines.

There are system losses of course but overall as there are no moving parts and the vortex tube is insulated, system losses are minimised as much as possible. The calculations that require verification by the prototype are simple.

To prove that the innovation can cool a space, the experimental POC will use a 1m3 triple walled acrylic box with argon infill in the walls to reduce thermal gain.

The acrylic will be recycled in line with the sustainable objective and reduction targets for embedded carbon of the unit.

One variant will cover the 1m3 acrylic cuboid container in a reflective cover to reduce thermal gain due to light and EM radiation.

The other variant will keep the cuboid container transparent and allow EM gain.

The cuboid 1m3 container will be contain the torodial venturi system (see images) and the ducted fans will ‘pull in’ air from the space to be cooled. The cuboid container size is adjusted to allow for the displacement volume of the torodial venturi vacuum system.

The vortex tube and energy recovery system will outside the container. A standard vortex tube of 23 cm -27cm will be used without modification. This will be coupled with the tabers system. The hot stream outlet will be set at 20% of the peak mass flow rate and the cold outlet will be set at 80% of the peak mass flow rate to optimise cooling.

BLDC fans with a minimum 15,000rpm will be used to power the torodial venturi vacuum loop and they will also be used along with a rectifier to become microgenerators within the torodial energy recovery system. Each fan will have a flow rate of 0.5m3 per minute for a total combined flow rate on 6 fans of 3m3 per minute.

The tabers system will be fluidically coupled with the torodial venturi system by connecting the venturi vacuum inlets to the tabers energy recovery outlet.

Calculations, Outcomes and Comparisons

What is the energy consumption of the highest energy rated fridge by way of easy comparison. An air-conditioning unit could also be used and the energy consumption factored down as the cuboid is a representation of a space requiring cooling. However, a fridge which is also a fixed space offers easier analogous comparisons.
According to the energytrust.org, Home appliances and energy efficiency ratings - Energy Saving Trust, an A energy rated fridge consume 123KWH per annum with a capacity of 0.8m3. For the purpose of easy comparison, we will assume that the 1m3 cuboid area to be cooled is analogous to a large standard fridge consuming 123KWH per annum even though it is larger than a typical fridge and should take more energy to cool.
The innovation has to show that its energy use is at least 50% more efficient than the current cooling methods, so we would expect an annualised 61.5KWH of energy to be consumed or less.
The innovation does not use polyurethane as insulation which is difficult to recycle and is a pollutant.
The innovation does not use refrigerants which are difficult to recycle and dispose of creating a mountain of rubbish and landfill globally.
The innovation will be at least 90% recyclable and manufactured from 75% recycled materials. |
The innovation has several objectives. Does it generate enough from the concentrated thermal energy from the hot stream of the vortex tube (rejected heat) to offset the parasitic losses of the fans pulling in the air from the fridge to achieve the target temperature.
1m3 of air at 25oC (standard testing temperature) contains enthalpy of 25.125KJ. 1m3 of air is 1kg. Enthalpy is the total internal energy of a gas. The target temperature for the air inside the 1m3 cuboid is 2oC. The enthalpy of 1m3 of gas at 2oC is 2.01KJ. Under conservation of energy rules and allowing for system losses of 10%, 20.5KJ of thermal energy is rejected by the hot stream of gas exiting the vortex tube.

20.5KJ of energy is available to convert into electricity via microturbines. If the turbines are 50% efficient, then 10.25KJ of electricity will be produced. If it is 25% efficient, then the 5.12KJ of electricity will be available as electricity.
The innovation will assume published results on the output of vortex tubes at 1bar. In reality, the torodial venturi vacuums will produce more than 1 bar pressure. Assuming just 1 bar and a flow rate of 3m3 per minute, the vortex tube will produce 4oC of cooling per M3 of air processes. Thus to achieve 2oC, the air inside the 1m3 cuboid container will need to be passed through the vortex tube 6 times. This means the fans will need to operate for 2 minutes. The total power consumption of the fans should be less than the 5.12KJ – 10.25KJ of energy recovered from the energy recovery system.
If this is proved, then the system does not require external power to operate EXCEPT for the initial priming to start the fans which will require a rechargeable battery. This will be powered from the recovered energy from the rejected heat.
If the energy recovered is less than 5.12KJ, then the innovation will be judged on its efficiency improvement compared to conventional systems. The innovation will undoubtedly consume less than 61.5KWH per annum which is 50% better than the highest energy efficient refrigerator in use today.
The applicant believes that the physics support its assertion that the conversion of rejected heat to electricity via the micro-turbine energy recovery system will be more than the amount of energy used to power the fans. Please note that the thermal energy is air is being converted and concentrated by the vortex tube which literature shows can produce temperatures as high as 180oC from the hot stream of a vortex tube.