Latent Power Turbines(TM)
Patent application Nos. GB1418029.3 GB 0807276.1, 0618171.3, 0903879.5
A Latent Power Turbine is a heat engine inside a mechanical engine
The heat engine generates electricity and the mechanical engine recycles the waste heat
Patent Office searches indicate that Latent Power Turbines are unique among heat engines in their ability to recycle their own waste heat.
Q. What do heat engines do?
A. Heat engines convert heat into a more useful form of energy.
In motor cars they provide energy to keep the car moving and in power stations they generate electricity.
Unfortunately the laws of thermodynamics limit the amount of useful energy we can squeeze out of a heat engine.
Can engines throw away about 70% of the heat and power station turbines waste about 50%.
Latent Power Turbines overcome the efficiency problem by recycling the rejected heat.
Bizarrely, we have found that the best way of recycling the heat is to run the heat engine at a temperature cooler than the laboratory air.
[It took the guy in the photograph below 40 years to feel at ease with with the strange concept of a cold heat engine. No wonder his hair is grey!]
When the Latent Power Turbine is switched on, his hands become chilled because the system cools when it generates electricity.
HEAT FROM HIS BODY is flowing into the Latent Power Turbine and converted into electricity.
In contrast, if he had been touching a car engine or power station turbine casing, he would have received a nasty burn as heat flowed into his hands.
Q. How do you make a heat engine run cold?
A. The working fluid for our heat engine is dry air at atmospheric pressure. We use a fan to keep the air moving through a wide pipe (conduit) at low speed. Then we taper the conduit so that the air is forced to move faster and gain kinetic energy.
Energy cannot be created or destroyed, but it can change from one form to another.
In this case, the air cools below laboratory air temperature to offset the gain in kinetic energy.
It then suffers a further drop in temperature to offset the energy output as electricity.
The tapered section always forces the heat engine to run at a lower temperature than the surrounding environment. This means that LP Turbines have the potential to extract heat from their environment for use as fuel anywhere on the planet, from the equator to the poles. In cool damp environments such as the UK in winter, there could be icing problems. Fortunately, Queens University Belfast (and others) are are developing surface coatings that should prevent icing up.
Latent Power Turbines have to consume some electricity to operate the fan, but the commercial product will be capable of generating a net output of power by converting heat into electricity. The following diagram explains the principles involved.
The formula linking electric power input and output is discussed on our technical theory page.
Current state of research
All of our funding to date has been spent on building the test rig. This meant that the turbine rotor had to be improvised using a set of air conditioning fan blades working in reverse. This crude arrangement was adequate for demonstrating that the temperature and pressure changes around the system were in line with our expectations. But the blades were entirely the wrong shape to generate a useful power output.
We do not have the specialist skills required to design a bespoke turbine, but this is our understanding of the change in the shape of the rotor blades required:
We are currently seeking additional funding to design a bespoke set of turbine blades and install an improved turbo-generator inside our test rig.
Likely commercial LP Turbine designs
(i) Large commercial LP Turbines could take the form of a daisy chain of alternate turbo-generators and fans.
The turbines will include two or more sets of counter-rotating rotors.
This is one of the daisy chain loops described in our patent literature. Note the use of parallel sided conduits.
LP Turbines are self correcting. If insufficient heat flows in from the environment to offset the electricity generated, the working fluid will cool. This increases the temperature gradient between the interior and exterior of the conduit, increasing the rate of heat flow.
Small scale LP Turbines
For domestic and small business purposes, the following plenum chamber design will be more compact.
Figure 8. We envisage that the small (approx. 12 kW) Latent Power Turbine for domestic and small business use will be completely different in shape to our research prototype. But the scientific principles that underpin the design will be the same.
Basic models would include a starter rope, similar to that used on outboard motors, to start the fan moving. Other options for getting the air flowing include installing a lead-acid battery and starter motor unit, as used for car engines.
Estimating a retail price
Mechanically and electrically, this design will be no more complex than a domestic washing machine.
The construction materials required will probably be equivalent to those required for two washing machines, giving us a an estimated retail cost of about £600.
This is likely to be lower than the cost of the home energy storage batteries alone that will be required by the UK governments current energy plan. And of course, the average life of an LP Turbine will be far longer than that of a storage battery.
Finding out more
To comply with patent law and other technical reasons we have omitted some details from our website. If you need further information, please get in contact with us.
Innovate UK (A British government agency) funded our early research at Lancaster University. We then went on to win £98,400 additional Innovate UK funding to test our deigns on a larger scale. The larger rig, as illustrated on this page, was built for us by C-Tech Innovation Ltd.