Stirling + Heatpump = Free Energy?

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Response to Stirling + Heatpump = Free Energy?

Postby arnoldlaine » Mon May 26, 2008 1:30 pm

Further to my other comments the secret to the heat pump Stirling engine theory is the reuse of the waste heat from the Stirling engine.

For instance a Stirling engine might only produce 20 percent motive force but the heat losses can easily be recycled via the heat pump.

Stirling engines need a temperature difference to work.

Heat Pumps using change of pressure and change of matter state do not require a positive temperature difference and in fact can pump heat from a colder mass to a warmer mass thus producing a significant increase in temperature difference.

Heat pumps are looking for sources of heat this is why it is so easy to recycle virtually all the lost heat back through the heat pump.
Heat pumps can have COPs of over 6.
It is the heat pump that is key to the system working and producing free energy from the environment. The Stirling engine that is used can be relatively inefficient because the heat pump can reuse the waste heat.

Practical free energy should be possible but remember that no more energy goes into the system than comes out. Thus no laws of physics are broken.

Even with a simple thing like opening a window we use very little power but the energy flow through the window can be many thousands of times more than the effort used to open the window.

In the summer months in the Temperate regions of the Earth virtually all our heating is free from the sun and in the winter we still only pay for about 2 percent of the heating costs. The other 283 degrees are free. Think about it. Absolute zero is minus 273 degrees C. That is where we would be without the free heat from the sun!
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Response to Stirling + Heatpump = Free Energy?

Postby gregory.hickling » Wed Jul 29, 2009 3:25 am

This is obviously an intriguing idea. It should work as long we don't loose sight of what is actualy being achieved.

Think of the process as a bit like an electrical transformer or hydraulic ram pump. An electrical transformer converts from 'many electrons at low voltage' to 'few electrons at high voltage'. A hydraulic ram pump converts from 'large amount of water with low pressure energy' to 'small amount of water with high pressure energy'. In both cases there is an energy balance so no laws of physics are contravened.

Here we are fundamentaly talking about a thermal transformer. The heat pump is the core of this, it can push heat from a low temperature to a high temperature, it just requires a motive force. In this case the Stirling engine is envisaged to provide this. Now, if we look at it very simply we are considering 'large amount of heat at low temperature' to 'small amount of heat at high temperature'. From this model it becomes abvious that:

1. just as a certain number of electrons must 'drop out the bottom' of the electrical transformer and a certain amount of water must 'drop out the bottom' of the hydraulic ram then in this case a certain amount of heat (at low temperature) is going to have to 'drop out the bottom';

2. efficiency is important in all stages if this is going to work.

Point one indicates that there must be some real energy balance where this system is going to work so we just have to keep at it until we have worked out the details. Point two indicates that talk of 'the Stirling motor can be inefficient because the energy is free' is at least missguided if not simply wrong. Put simply, as motor efficiency falls then ever greater amounts of heat must 'fall out the bottom' for every Joule we push to higher temperatures. Eventually we will be leaking all the energy available out of the motor and there will be nothing left to drive the pump.

Using analogy (and working from gut feel) the afficiency of the heat pump will be most important for the temperature to which we can push the compressed heat. As efficiency falls in the pump then it will become increasing difficult to achieve a usefull temperature increase. Sooner or later the heat just gets moved with no temperature increase at all. However, this last point is a bit windy especially as we can probably not seperate the efficiencies and products of the two machines this cleanly.

Furthermore, statements like 'Low efficiency is o.k. because the energy is free AND WE CAN USE THE WASTE HEAT TO HEAT WATER OR SPACE.' also miss the basic point. We wanted to get some kind of mechanical work out of the system even if only for internal use. If you are just interested in the heating effect then drive the heat pump with an externaly powered electric motor and get all the high temperature heat you could ever need. The point was to avoid the external inputs and make the system self-sufficient at the very least.

So in concluson, I would suggest that as long as we start with sufficiently large hot and cold heat sinks with a useful deltaT and have sufficiently good mechanical efficiency in the mechanical parts we could certainly get both high temperature heat and excess mechanical work out of the system.


P.S. (Working from memory) I once heard of a system that did just this. The Festival Hall in London was built with a Stirling motor/heatpump heating system. The heat sinks were ambient air and river water (it is located next to the Thames river). It did work, at least as a scientific show piece, but was later replaced by 'cheap' fossil fuel heating. The reasons for this may have been to do with maintenance costs. If you dig around in the internet you might find some references to it, I am just too busy at the moment.
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Response to Stirling + Heatpump = Free Energy?

Postby stan.hornbaker » Wed Jul 29, 2009 8:08 am

QUOTE:So in concluson, I would suggest that as long as we start with sufficiently large hot and cold heat sinks with a useful deltaT and have sufficiently good mechanical efficiency in the mechanical parts we could certainly get both high temperature heat and excess mechanical work out of the system.END-QUOTE

A Stirling engine used as a heat pump or cryo-cooler works best at temperatures below atmospheric and requires mechanical work input to drive it. There is NO excess mechanical work output from such a system.

As always there if no free lunch. Capiche?
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Response to Stirling + Heatpump = Free Energy?

Postby sinimil » Sat Nov 21, 2009 7:29 am

Dear Mr. Pranab Jyoti Ghosh,

Part of your project resembles my project for extracting unsolted water from sea. You said for your self that your project is a collection from different branches of industry, but you didn't know it also contains parts not yet accepted for wide use.

Ok, VacEx (Vacuum Extraction) Process goes like this:

15m high cone has wide end in sea. On top of it is vacuum pump, pulling vapor from inside.

About 15kW pump is needed for extracting 5 kg/sec. Vapor goes down through spiral pipe in the wall of cone, with narrow valve on exit. Narrow valve creates pressure, which returns heat from the pipe to sea water inside the cone. Being physics graduate, you know the parabolic function of water evaporization depending on pressure.
This system extracts non-salty water from sea without micro-membranes.

Why cone? It can not be simple vertical pipe, because of salt crystalized on inner water surface during evaporization. When crystals become big enough they sink, removing themselves automatically from inner surface covered with teflon.

Water returned through pipe goes out, to fields, or to further treatment.

Ok, I know this is not all about energy ballance, but in this project you have temperature difference which can be used by Stirling engine to reduce energy needed for vacuum pump.

Thank all of you for your time.

Sinisa Milisavljevic, Beograd
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Response to Stirling + Heatpump = Free Energy?

Postby res0inod » Mon Dec 07, 2009 5:17 pm

Interesting idea. I'm a HVAC tech and marine tech, as well. Just started to study SE's.

Thinking of solar dish heated Stirling generator as the basic plan, and then why add a refrigeration loop in parallel??

But it does make some good sense. Use the Stirling gen to first start making power while the sun shines, and get the frige loop running on the supplied power. When the sun goes away the frige loop would continue to collect heat unless it's not grabbing heat from a good, steady source.

I've installed ground source heat pumps that a extremely efficient, and I hear water source are great as well. These are more costly to install but are worth it.

Combine the above with a proper interface to the power grid and you could make money. A battery bank and inverter, metalhydride/H2 system could be used for off grid application. H2 can be burned at night to keep the SE gen fired up.

Use an insulated water reservoir/loop to supply the frige loop and/or the sun could heat a pool, or an integration for home heating.

Such systems would need the mentioned 'regulator'. The dish can be aimed away from the sun. Excess heat can be stored in the earth or in a water loop.

The SE section sizing is the key. The more power it produces the better.

There's a vid on Utube or someplace showing a guy running a 15kw gen by shining an array of truck mirrors (maybe 10 x10ft) on a boiler that feeds a steam eng. That's impressive! Supposedly the Stirling eng is more efficient.

What Good Fun!
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Response to Stirling + Heatpump = Free Energy?

Postby bptdude___2569 » Mon Dec 07, 2009 6:18 pm

Hi David,

You got two thumbs up from me.

You seem to have the concepts correctly balanced, as well as the ability to do them. I am really a pain to so many people here, thought I would mention when I saw one that was right on.

Now, how do we clone you and have enough of you in all the places people would like such things installed?

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