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Solar Thermal Waste Heat Engine works at low temperature, low pressure


February 12, 2009

Cyclone Power Technologies - Waste Heat Engine

Cyclone Power Technologies - Waste Heat Engine

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February 13, 2009 Technology capable of generating electricity by extracting energy from heat that is otherwise just wasted is a fairly new branch of renewable technology. A typical co-generation plant uses waste heat from a gas or steam turbine for hot water or space heating. This Waste Heat Engine (WHE) developed by Cyclone Power Technologies operates at temperatures as low as 225F (107 C). The engine can generate up to 10kw from heat sources such as industrial ovens or furnaces, concentrating solar thermal collectors, engine exhaust and biomass combustion.

The compact, lightweight 18 lb (8 kg) Waste Heat Engine is a six-cylinder radial steam engine capable of running on waste heat as low as 225 °F (107 °C) and pressure as low as 25 psi (172 kPa). The engine achieves maximum efficiencies at 600 °F (316 °C) and steam pressure of 200 psi (1.4 MPa), at which point one Waste Heat Engine can generate 16 hp (12 kW), 30 lb-ft (41 Nm) of torque, and a little over 10 kW of electrical output. The only drawback is the typically low 12% energy efficiency common with most reciprocating steam engines. On the plus side the piston-based steam engine operates at a maximum of 3000 rpm which means it is well suited to drive any standard generator.

Due to its patent-pending valve mechanism and radial spider bearings, which allow for efficient piston movement, the WHE will self-start immediately upon the introduction of steam to the cylinders. This makes the engine well suited for passive or secondary energy production like co-generation or small scale solar thermal applications.

Over the following months, the company's new WHE/Generation division will launch a consumer-oriented web site, and contract with manufacturers and installers to handle forecasted sales of these systems.

The first WHE system will be installed at Bent Glass Design in Hatboro, PA. This system will harness waste heat from the customer’s glass manufacturing furnaces, and is expected to produce enough electricity to light their 65,000 ft2 facility while providing a quick payback possibly within two or three years.

Paul Evans


What happened to acid dewpoint?

At the extremely low temperatures heat is often useless due to acid characteristics of the gas stream.

This is probably a useless invention.


euss, even if you were correct, the invention would still be a far greater contribution than your comment. Who ever said you had a clue?

The idea is amongst the G2 concepts, which rightly suggest we make secondary use, recycle, per se, the energy. It makes perfect sense. When we use a gas heater, it's foolish that we don't install a heat exchange unit in the exhaust pipe, to heat fresh water as well. It's wasteful not to make full use of the energy expended.

John Taylor

You\'d think, with all of this tech know-how that the diagram of this contraption would be legible. That low-rez image was so bad that I couldn\'t make out a single word of it...? Stop putting up useless photos and diagrams. It undermines the importance of the items in question. Not too much to ask, is it?.


An interesting engine. Presently the highest Solar to Grid efficiency is held by the Parabolic dish/stirling engine combination. How is this engine equal to or better than a stirling engine? Could it be practically combined with a parabolic dish for a stationary application. Traditional steam engines have enough torque at low end to not need a transmission. How does this engine compare. Nice article but results in more questions than answers.


STERLIN engines operates in these realms also,.. but requires high precision manufacturers, like a taiwanese machine shop,.

Søren Algreen-ussing

I would like to know if it is possible for a stirling engine to generate power at room temperature. It sounds like an impossible perpetual motion energy system but it will be decreasing the temperature of the area around it. What are the problems with this system.

Yusuf Khan

how is it that there are large pools FULL of spent nuclear fuel that need extreme amounts of cooling and yet on has figured out a method of using technology such as this in order to turn the COPIOUS amounts of heat from spent nuclear fuel into electricity.


@Khan: It IS entirely possible to make a Stirling engine run at room temperature. Being a \'heat\' engine, you always need a temperature differential between the hot cap and the cold cap. Fortunately, as you reduce the Height/diameter (or Length/ diameter, your preference) the required differential becomes LESS. So, a large diameter, squat profile would yield an engine that runs on say, sunlight as long as the cold cap was, say, in contact with the cold ground... Remember, it IS a heat pump, so its always moving heat from the hot cap to the cold cap. To all the rest: As I recall, when \"big Nick\" Tesla was a young boy, he invented a device called a bladeless turbine. This reduces precision machining to near zero and runs on the flow of any fluid flow, be it gasseous or liquid. I wonder A) how the efficiency stacks up against other \"shaft drivers\" and B) how long it will take the alternative energy community to \"rediscover\" this device. Quite a kid that Nicky! BTW, Edison allowed him to test it out at the Niagra Falls power station and the results, as reported to me, were 200 Hp (150 Kw) in a box 2ft x 2ft x 4ft. Also, some folks have made these using a stack of CDs.


A lot of time ago NSU had publicated about the part of the rods and crakshaft of a thermic engine in the parasitic resistances. It was a very little part, the big one beeing due to rings and piston. The camshaft levers, valves and springs had a modest contribution, that was a good surprise. A lot of things change with the time. A lot of other change with steam use instead of combustion. For example, the law of the de-compression must be very important and favorise long stroke. The Cyclone steam engine has a long stroke ? I worry it is difficult with this spider bearing and a six cylinder star disposition. Short stroke is a nice thing to favourise high revolutions, in the case of a low-pressure steam engine and his 3,000 RPM... hum! Each time I see a new way to escape at a crankshaft or to have a better one I remember that a crankshat is a very good way to change an alternative movement in a rotative one ... or the contrary !


Very nice to see anyone with Faith. But Burnerjack may not ignore longer that Tesla Turbine is difficult to tune. The high efficiency we hope is not always obtained but always the torque is very low out of the RPM range. Perhaps it would not be a big problem to produce electricity, but for other use ? Experiments with compact disk are nice but dont allow steam use ! Anyway I mind a part of the reasons of the Tesla turbine difficulty with real world remains in the fact that the fluid goes the wrong way. I mean in a Tesla engine, not in a Tesla pump. At less it makes the demonstration that the boundary layer is well glued to the disks. It looks difficult to enter steam by the center. But is it imposible ? Indeed it would not be more a Tesla turbine, and would have lost a lot of interest for the Tesla Lovers. Bernardin.


zevulon, I was wondering the same thing when Fukushima was melting down and spare generators didn\'t work. The rods are hot enough to make power to run cooling pumps...


to and about dsiple\'s comment; Can\'t we build nuclear energy plants on-top of a lake or pond big enough to drown and thus cool a melt down situation of a nuclear facility? seems simple to me? if u take this idea and use it please credit \'gizmag user\' hogi90 thank you. i hear that simple is better. i have also figured a way to stop the flooding in the mid-west of the USA. so if anyone knows a site that could use my suggestions try to contact gizmag user hogi90 thanx


When I learned years ago that some power turbines use a heat capture system, it got me thinking about scaling that down to anything putting out heat, like a car engine. I figured that maybe the thermo-electric effect was the go. This system, while containing plenty of moving parts, might be better? Either way, lurve the way they're thinking!

John Hogan

OK, friction goes up as a square of the speed, so for any given displacement of any engine, with all other factors being relatively equal, the same amount of power will be generated. Yes, you get more torque with a longer lever, but in order to maintain the same cubic whatever displacement figure, you need to DECREASE the piston diameter (area), thus losing pushing force. The mean piston speed is the same as there is a longer dwell time at both TDC and BDC, but the center velocity of the piston will go up with a longer stroke length. The strain on the connecting rods will be higher in the longer stroke engine as more inertia is present in the piston. Inertia goes up as a square of the speed too, that's why a vehicle needs four times as much room to stop each time you double the speed. Torque is basically a function of compression ratio and volumetric efficiency, horsepower is a function of compression ratio and RPM. How much fuel you burn determines how much work you can do. Did I miss anything here?

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