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Mark Johnson

Jun 17, 2014
10:39

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You did your homework to the max. EVIDENCE: https://www.climatecolab.org/web/guest/plans/-/plans/contestId/1300201/planId/1307129

Patrick Mcnulty

Jun 17, 2014
10:03

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Thanks Mark I try hard :)...

Sardar Mohazzam

Jun 18, 2014
06:21

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Hello - Your proposal has no references. Have you left it intentionally to be filled later ? or you didn't find any research work done ? Electricity generation companies worldwide are always focused on efficiency. How your idea have never been thought by anyone ? Check may be there is some similar model or close to what you are proposing is there. It will strengthen your ideas validity.

Patrick Mcnulty

Jun 18, 2014
08:13

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Hello Sadar, As far as I know no studies have been done. I worked for FP&L down in Miami Florida for 20+ years as a production leader and control room operator at many of their fossil fuel power plants and never heard of this concept. Anyways, I am sure some of that wasted heat can be utilized in this manner. Anything to drive down heat rate is a good thing.. Feel free to check my other proposals here at MIT Climate CoLab and don't forget to click support proposal icons.. :)

Mark Johnson

Jun 18, 2014
09:56

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Being in a plant setting for 20 years and having nobody tell you about it, means this idea is indeed epic and Seminole!

Mark Johnson

Jun 18, 2014
09:52

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Google this: Increasing the Efficiency of Existing Coal-Fired Power Plants www.fas.org/sgp/crs/misc/R43343.pdf Federation of American Scientists by RJ Campbell - ‎2013 - ‎Cited by 2 Dec 20, 2013 - Congressional Research Service. 7-5700 ... The overall efficiency of a power plant encompasses the efficiency of the various components of.

Patrick Mcnulty

Jun 18, 2014
02:36

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"Being in a plant setting for 20 years and having nobody tell you about it, means this idea is indeed epic and Seminole!" Thanks Mark, Epic and Seminole.... I hope that's a good thing.. :)

Mark Johnson

Jun 18, 2014
08:54

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It's OK. Epic is an IMPACT of "game changing importance." Seminole, is "a point in time which is game changing." Both super impactful. Mark

Patrick Mcnulty

Jun 19, 2014
03:59

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Sounds super Mark... Glad to lower heat rate.

Michael Brown

Jun 20, 2014
09:14

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Thank you for submitting this proposal. I agree that heat recovery applications are an excellent opportunity to make use of waste and improve overall plant efficiency. I have a few questions/comments: 1. Can you explain how you get the 7% figure? Do you mean that for every 100 units of energy in (i.e. heat content of fuel) you can get 7 units out, or do you mean for every 100 units of electricity you can get an additional 7 units, or for every 100 units of heat you can get 7 units of electricity? Some explanation of the energy balance would be helpful. 2. Why a Rankine Cycle specifically and not another method of thermal electricity generation? 3. Any other options beside freon? Some types have been banned under the Montreal Protocol and others are known as very potent greenhouse gases. 4. I highly recommend developing your cost estimate in greater detail. Assuming you put this on a baseload generator, you're getting 7 MW * 8760 hours = 61M kWh per year. At a wholesale cost of 5 cents / kWh that's 3M per year, meaning you have a simple payback period of 1 year (assuming 'a few million' means 3). This is a very good business proposition and I find it difficult to believe that power producers (who are, after all, business people) have not jumped on this opportunity. 5. A discussion of the barriers to implementation would be helpful, as per comment 4. 6. An explanation of the technology itself would complement your theoretical presentation of the Rankine cycle. In addition, some estimate of the potential for this technology/approach would provide context. 7. I refuse to believe you couldn't find any references to Rankine Cycle engines, or heat recovery devices for that matter. Have you tried Googling 'Rankine Cycle Engine' or looking in any introductory thermodynamics textbook?? Best of luck, Mike

Patrick Mcnulty

Jun 22, 2014
07:51

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Hi Michael, Yes there is a lot of wasted heat in many areas of today's industrial world. It would be great if we can use that wasted heat to our advantage and make electrical power from it. I'll be glad to answer some of your questions here. "1. Can you explain how you get the 7% figure? Do you mean that for every 100 units of energy in (i.e. heat content of fuel) you can get 7 units out, or do you mean for every 100 units of electricity you can get an additional 7 units, or for every 100 units of heat you can get 7 units of electricity? Some explanation of the energy balance would be helpful." In today's power plants 13% of the plants heat goes right out the stack. My plan is to recover 7 Megawatts out of every 100 megawatts of heat energy from that gas flow going to the stack from the air preheaters thus raising plant output that much using this method of heat recovery. This would lower the total plant heat rate a lot. "2 &3. Why a Rankine Cycle specifically and not another method of thermal electricity generation?" A"ny other options beside freon? Some types have been banned under the Montreal Protocol and others are known as very potent greenhouse gases." I Would like to use this method because freon boils at around 72 degrees F at atmospheric pressure. Usually stack gas is near 200 degrees F and so water would not boil. Bromine may work but I think it boils near 170 degrees F. Ammonia is another option but it is pretty hazardous stuff if it leaks out. Other liquids with low boiling point are flammable so I think you can the danger there. So I am thinking freon would be the best material since it is so widely used already.The modern day compounds of freon are not as hazardous to the ozone layer.. The most likely place for a leak would be near the mechanical seals so we can build a freon seal leak recovery system for that if it were to happen.. "6. An explanation of the technology itself would complement your theoretical presentation of the Rankine cycle. In addition, some estimate of the potential for this technology/approach would provide context." I have only heard of this technology used in Ocean Thermal Energy Conversion ( OTEC ) and I believe this technology would be transferable for other uses where heat is wasted specifically large heat sources like power plants or other industries. This link on Wikipedia is pretty informative. http://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion "7. I refuse to believe you couldn't find any references to Rankine Cycle engines, or heat recovery devices for that matter. Have you tried Googling 'Rankine Cycle Engine' or looking in any introductory thermodynamics textbook??" It's not that I couldn't find any references for OTEC technology per say but I couldn't find any references to use it in the manner I wish to.. Thank's, Pat

Patrick Mcnulty

Jun 22, 2014
07:44

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Just did a search on Bromine it boils at 138 degrees F. so it may be a candidate also...

Climate Colab

Aug 13, 2014
04:20

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The proposal involves re-capturing waste heat from the stack of power plants or other industrial facilities by using an ammonia based Rankine cycle to power a generator. The concept of capturing waste heat in this manner is well known and has been used extensively in industrial and even residential applications. For example, most commercially available residential high efficiency heating systems use a variation of this approach to capture heat from the furnace exhaust. Commercially available applications include utilizing the waste heat directly (e.g., to heat water) or to generate electricity (e.g., a combined cycle power plant).The gains in efficiency are currently funded, in part, by government mandates to achieve efficiency targets and, in some states, utility demand side management subsidies. A future proposal would be enhanced by:a) Identifying specific applications for the waste heat extraction that have not yet been tapped.b) An assessment of the reason that they have not been tapped and an explanation for how these problems can be overcome.