Comments for Solar Heat Engines http://www.solarheatengines.com Simulate, analyze, design, build, and test solar-powered engines Wed, 01 Feb 2012 23:07:51 +0000 hourly 1 http://wordpress.org/?v=3.3 Comment on Self-starting solar-powered Stirling engine by admin http://www.solarheatengines.com/2011/09/21/self-starting-solar-powered-stirling-engine/comment-page-1/#comment-648 admin Wed, 01 Feb 2012 23:07:51 +0000 http://www.solarheatengines.com/?p=565#comment-648 I hadn't though of doing that. I have thought of of using hot and cold sources that use water (and perhaps antifreeze). Use solar heating during the day for the heating and radiation and convection at night for the cooling. A small engine such as the one I have shown could probably run continuously on this setup. The idea is to use a vertical column of water as a diode, allowing heated water to convect up vertically. When the bottom is cooler than the top, convection does not occur and only conduction transfers heat. Conduction in water without convection results in far lower heat transfer rates. The entire heating and cooling system could be designed to work on convection without pumping. I hadn’t though of doing that. I have thought of of using hot and cold sources that use water (and perhaps antifreeze). Use solar heating during the day for the heating and radiation and convection at night for the cooling. A small engine such as the one I have shown could probably run continuously on this setup.

The idea is to use a vertical column of water as a diode, allowing heated water to convect up vertically. When the bottom is cooler than the top, convection does not occur and only conduction transfers heat. Conduction in water without convection results in far lower heat transfer rates. The entire heating and cooling system could be designed to work on convection without pumping.

]]> Comment on Self-starting solar-powered Stirling engine by shadowraven http://www.solarheatengines.com/2011/09/21/self-starting-solar-powered-stirling-engine/comment-page-1/#comment-647 shadowraven Wed, 01 Feb 2012 20:43:33 +0000 http://www.solarheatengines.com/?p=565#comment-647 Have you considered using the difference between air temp and soil temp at around 15-30 feet? (A geothermal heat pump) As you approach 30 feet of depth, most soils maintain a fairly steady temperature year-round (within a few degrees of the total average temperature which is about 62 deg F where I live) The air temperature can easily fluctuate +/- 40 degrees of that average temperature. It's not a lot, but it would work equally as well in the summer as in the winter (as the fluctuation between hot and cold side would be similar)... the tradeoff is that it wouldn't work well at all in the fall and spring months when air temperatures approach the average yearly temp. Have you considered using the difference between air temp and soil temp at around 15-30 feet? (A geothermal heat pump) As you approach 30 feet of depth, most soils maintain a fairly steady temperature year-round (within a few degrees of the total average temperature which is about 62 deg F where I live) The air temperature can easily fluctuate +/- 40 degrees of that average temperature. It’s not a lot, but it would work equally as well in the summer as in the winter (as the fluctuation between hot and cold side would be similar)… the tradeoff is that it wouldn’t work well at all in the fall and spring months when air temperatures approach the average yearly temp.

]]> Comment on Tamera video of Sunvention SunPulse engine by admin http://www.solarheatengines.com/2012/01/10/tamera-video-of-sunvention-sunpulse-engine/comment-page-1/#comment-643 admin Fri, 27 Jan 2012 19:24:10 +0000 http://www.solarheatengines.com/?p=746#comment-643 The Sunvention site does state the cylinder for the electric generating engine is 2m x 0.5m, but it isn't clear what that dimension is for. Is it the outside of the displacer housing (which is how I interpreted it) or the actual cylinder bore (which is how I think you are interpreting it)? After carefully comparing it with the flywheel diameter and the person in the video (only an eyeball comparison) I decided on the 48 inch bore. If I increase the power piston bore estimate to 60 inches, then my power estimate comes out close to 1500W. The Sunvention site does state the cylinder for the electric generating engine is 2m x 0.5m, but it isn’t clear what that dimension is for. Is it the outside of the displacer housing (which is how I interpreted it) or the actual cylinder bore (which is how I think you are interpreting it)? After carefully comparing it with the flywheel diameter and the person in the video (only an eyeball comparison) I decided on the 48 inch bore. If I increase the power piston bore estimate to 60 inches, then my power estimate comes out close to 1500W.

]]> Comment on Power Piston Sizing by admin http://www.solarheatengines.com/2010/09/18/power-piston-sizing/comment-page-1/#comment-642 admin Fri, 27 Jan 2012 19:20:27 +0000 http://www.solarheatengines.com/?p=393#comment-642 I'll post a guide for sizing your power piston within a few days. After that I'll see if I can come up with some useful guidelines for flywheel sizing. I’ll post a guide for sizing your power piston within a few days. After that I’ll see if I can come up with some useful guidelines for flywheel sizing.

]]> Comment on Power Piston Sizing by SANTOSH KUMAR http://www.solarheatengines.com/2010/09/18/power-piston-sizing/comment-page-1/#comment-636 SANTOSH KUMAR Wed, 25 Jan 2012 12:53:11 +0000 http://www.solarheatengines.com/?p=393#comment-636 i need the dimensions of the power piston and flywheel . how to calculate the dimensions i need the dimensions of the power piston and flywheel . how to calculate the dimensions

]]> Comment on Tamera video of Sunvention SunPulse engine by Ed Golla http://www.solarheatengines.com/2012/01/10/tamera-video-of-sunvention-sunpulse-engine/comment-page-1/#comment-622 Ed Golla Sat, 14 Jan 2012 13:44:30 +0000 http://www.solarheatengines.com/?p=746#comment-622 Thanks for the info and analysis. The variable displacer stroke is interesting. It could allow tuning for different TH and TC. The sunvention site states that the cylinder for the electric generator is 2m by 0.5m. This is almost double your estimate. Thanks for the info and analysis.
The variable displacer stroke is interesting.
It could allow tuning for different TH and TC.

The sunvention site states that the cylinder for the electric generator is 2m by 0.5m.
This is almost double your estimate.

]]> Comment on Solar-powered Stirling engine design details by admin http://www.solarheatengines.com/2011/12/24/solar-powered-stirling-engine-design-details/comment-page-1/#comment-597 admin Tue, 27 Dec 2011 06:08:33 +0000 http://www.solarheatengines.com/?p=682#comment-597 The balancing I use on this engine is just simple static balancing. When the crank pin for the displacer is horizontal (3 or 9 on a clock face), I weight the flywheel (also at the 3 or 9 position) so it balances in that position. Then I turn the crankshaft 90 degrees so the power piston crank pin is horizontal and add weight to balance it at that position. All this is done without compression. Now the flywheel can be turned to any position and it should stay there. I suppose there are inaccuracies caused by the connecting rod length but they are minor. Above 100 rpm or so you don't even need to do this type of balancing. The balancing I use on this engine is just simple static balancing. When the crank pin for the displacer is horizontal (3 or 9 on a clock face), I weight the flywheel (also at the 3 or 9 position) so it balances in that position. Then I turn the crankshaft 90 degrees so the power piston crank pin is horizontal and add weight to balance it at that position. All this is done without compression. Now the flywheel can be turned to any position and it should stay there. I suppose there are inaccuracies caused by the connecting rod length but they are minor. Above 100 rpm or so you don’t even need to do this type of balancing.

]]> Comment on Solar-powered Stirling engine design details by Alan http://www.solarheatengines.com/2011/12/24/solar-powered-stirling-engine-design-details/comment-page-1/#comment-595 Alan Mon, 26 Dec 2011 08:03:27 +0000 http://www.solarheatengines.com/?p=682#comment-595 Hi Doug Great detailed information. Good to hear you've exceeded your own design goal - that shot in the video showing the length of your own shadow really brings home how low the sun is at this point. Regarding balancing - and I realise how time-consuming creating all this is - could you make how you go about this a topic in a future post? I've an idea (hopefully wrong) that it's not as simple as it sounds... Thanks very much Alan Hi Doug
Great detailed information. Good to hear you’ve exceeded your own design goal – that shot in the video showing the length of your own shadow really brings home how low the sun is at this point.
Regarding balancing – and I realise how time-consuming creating all this is – could you make how you go about this a topic in a future post? I’ve an idea (hopefully wrong) that it’s not as simple as it sounds…
Thanks very much
Alan

]]> Comment on Solar-powered Stirling engine prototype Part 3 by Solar Heat Engines » Blog Archive » Solar-powered Stirling engine design details http://www.solarheatengines.com/solar-powered-stirling-engine-prototype-part-3/comment-page-1/#comment-593 Solar Heat Engines » Blog Archive » Solar-powered Stirling engine design details Sat, 24 Dec 2011 21:55:00 +0000 http://www.solarheatengines.com/?page_id=655#comment-593 [...] to make it better (that part is for my own benefit too). Here are the links: Part 1 Part 2 Part 3 Part [...] [...] to make it better (that part is for my own benefit too). Here are the links: Part 1 Part 2 Part 3 Part [...]

]]> Comment on Solar-powered Stirling engine prototype Part 2 by Solar Heat Engines » Blog Archive » Solar-powered Stirling engine design details http://www.solarheatengines.com/solar-powered-stirling-engine-prototype-part-2/comment-page-1/#comment-592 Solar Heat Engines » Blog Archive » Solar-powered Stirling engine design details Sat, 24 Dec 2011 21:48:57 +0000 http://www.solarheatengines.com/?page_id=641#comment-592 [...] would recommend to make it better (that part is for my own benefit too). Here are the links: Part 1 Part 2 Part 3 Part [...] [...] would recommend to make it better (that part is for my own benefit too). Here are the links: Part 1 Part 2 Part 3 Part [...]

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