I've refined my ideas for the engines quite a bit.
After doing some thermodynamic calculations and expansion energy calculations, I have come to the conclusion that approximately 9.7% of the energy in C17H32O2 is expansion and the other 90.3% is thermal. Note that this does not include standard kinetic energy for being above 0K or nuclear energy, etc.
I chose the molecule C17H32O2 because I found that Biodiesel is composed of oils in the C12 to C22 range, with a certain percentage C, H, and O by weight. Using molar masses I coverted this mass ratio into a molar ratio and determined the molar formula for the average biodiesel molecule. (Inherent is the assumption of a linear or at least guassian distribution of molecule sizes from C12 to C22.) The particular molecule I chose was a methyl ester. I chose a methyl ester for my calculations based on the fact that biodiesel is formed from Waste Vegetable Oil (WVO) by transesterification to remove sugar parts. Methanol is most often used in this process although Ethanol or propanol could also be used for (apparently) lower yields. So I used this molecule:
CH3OC(O)(CH2)5CH=CH(CH2)7CH3
C17H32O2
This is a mono-unsaturated methyl ester and I think it is representative enough of Biodiesel for my calculations.
At any rate, the thermal energy contained is important enough to worry about, as the mechanical energy of expansion is about 1/10th as much. However, the mechanical energy is enough that we don't want to throw it away either!
First we build a standard diesel engine that burns biodiesel. Most of our modification has to do with the intake, exhaust, and cooling systems that support this engine. However, one of the main modifications is that it is now a "medium speed" diesel engine which runs at a fixed rpm to produce a specific frequency of alternating current. This current is then fed into our supercapacitor stack (SCS).
Instead of a regular cooling system, we are going to cool the engine block, exhaust, and oil all through heat exchangers. This heat is then transferred to hosing which contains an organic fluid which boils at 50-60'C. This boiling fluid is used in a steam turbine arrangement to produce further power. The electrical power from the steam turbine is also funneled into the SCS.
Because we are scavenging more energy from the same amount of fuel we can spend a bit of our margin to make our system cleaner and more efficient. We can do this by installing an oxygen condenser. Our exhaust, once cooled, is run through an oxygen condenser. CO2, N2 and H2O are released to the ambient environment while O2 is recirculated into the "air intake" (which is actually an "oxygen intake." Biodiesel does not contain nitrogen yet NOx are produced by diesel engines. This is the oxidization of N2 present in the air and which enters through the air intake. By providing a 90%+ combustion atmosphere we can reduce or eliminate NOx and also provide quick and complete combustion. Higher cetane fuels ignite earlier in the timing of a diesel and thus allow more complete combustion by the time the stroke has finished. By having 90%+ oxygen instead of ~21% oxygen we can allow even fuller and more complete combustion. This type of system could well be marketed in north america as a "clean diesel." One of the reasons diesel engines are unpopular in north america is the common perception that they are dirty. Biodiesel is, in fact, quite clean and an excellent solvent. As a result the system described above would, in fact, be an extremely clean running engine, producing only CO2 and H2O with no NOx or SOx produced.
The SCS, or supercapacitor stack, is an integral part to this system. It is a decent way to get multiple sources of energy converging. Supercapacitors currently do not have the energy density required to be the energy source for a vehicle. However, unlike batteries, supercapacitors have a high power density. This allows a SCS to act as a great power source for electric motors directly attached to wheels. A SCS would actually be fairly heavy but research in this area is advancing quickly. It may be true that a SCS could be reasonably weighted... I have not yet done any calculations. I would first calculate the maximal reasonable acceleration required, then the electrical draw by the motors, then calculate what is required of the SCS. It would likely be that either a larger diesel (and hence heat) engine is required or a larger SCS is required as an energy buffer. Some equilibrium between these sizes would likely yield optimal conditions. Naturally the draw will be larger for larger vehicles, such as passenger trucks, but these vehicles also have more space and weight capacity for a SCS than a commuter vehicle. I see this design as scalable.
June 21, 2007
June 08, 2007
My Supercar Design
I've been kicking around various ideas regarding vehicular propulsion for a while now, and they've finally crystallized into some sort of order. I'm going to try to lay them out below.
Fuel Source / Power / Drivetrain / Steering
For my fuel I have selected biodiesel. This fuel takes approximately a 1/4 to 1/3 of the energy it contains to produce.
This vehicle has only one fuel but contains two engines. One engine is a small compression engine in the style of traditional internal combustion engines. I expect an engine in the 100-500 CC range in size. The difference comes in how this engine is cooled. Instead of being cooled into the environment, the heat is used to power a heat engine, such as a small steam engine or turbine. This raises various issues which I believe that I can answer.
One is that water/steam is not used in the heat engine. It uses an organic compound instead which is circulated in a closed system. There are multiple reasons for this. One is that the selected compound can have different physical characteristics than water. A boiling point of approximately 60'C is good because temperatures are almost always less than that (else we would die) yet it takes little heat to cause it to evaporate. The vapour can then be recycled through a familiar looking radiator to be condensed into a liquid, which then is recycled into the heat engine.
Each of these engines is used to turn a driveshaft. These shafts are not connected to the wheels, however, through any sort of mechanical linkage. Any mechanical attempt to integrate the two would likely result in twisted metal and failure - a good reason it has not been used previously. Instead, these two engines turn generators (an electric motor running in reverse) to convert the mechanical energy to electrical energy at a high efficiency (perhaps 98%). This electrical energy has to be stored in a buffer zone.
This buffer zone could be a bank of super-capacitors. This is an area of research that is filled with activity - and success. Even if our current super-capacitor capability is slightly lacking my proposed use, I belief that we shall soon see super-capacitors suitable to this purpose.
Energy is continually drawn from the super-capacitor bank to drive electric motors individually attached to each wheel. It is possible to build a chassis which has room for an electric motor to be attached to each wheel and to rotate with the wheel as it turns. This allows each tire to have independent suspension, turning, and drive.
My proposed method for steering this versatile vehicle is a pair of joysticks, one for each hand. Simpler methods, or ones which utilize the feet, can be implemented, especially for vehicles which limit drive or steering to two of the four wheels. (Obviously it is not required to have drive or steering on all 4 wheels.)
Discarded Ideas
I have decided against both solar panels and electro-voltaic batteries. The above mentioned vehicle should theoretically be more efficient than both the hybrid cars we have now, and also the car developed at MIT which was covered in solar panels. The reason for this mainly stems from production costs. THe production cost for a Li-ION or Li-Polymer battery can be expressed in terms of energy units. The same goes for solar panels. To my current understanding, solar panels will not return any significant gain in energy over the course of their life beyond the energy cost of making them. In regards to batteries, there is a car, called the Tesla, which currently runs on Li-ion batteries. However the batteries have to be replaced after an estimated 100,000 kms. This is because the batteries are limited to a certain number of charge-discharge cycles before they are dead. Furthermore, Li-ion batteries slowly decrease in the amount of total charge they will hold from the time they are manufactured regardless of use or storage. In contrast to a Li-ion battery 1000 charge/discharge cycles, a super-capacitor can be charged and discharged over 10,000 times, vastly exceeding its energy cost to manufacture. As an aside, Li batteries are explosive and have various problems that are more easily circumvented in capacitors. Both capacitors and electric motors have very long lives that outlast their costs of manufacture.
Fuels
Biodiesel, as mentioned, is a fuel which has a 3:1 ration for energy stored:energy production cost. Biodiesel is different from regular diesel in that it contains little to no sulphur, but contains more nitrogen from the plants. A detailed analysis of this is beyond my scope, but I will briefly remark that Sulphur produces sulphuric acid in the atmosphere and contributes to acid rain. Likewise NOxs are produced from plant sources and contribute to acid rain in the form of nitric acid - small difference. These are long chain organic oils that have a relatively high expansion ratio under combustion.
Ethanol only has a 1.5:1 ratio in regards to energy carried:energy spent. This is obviously not as good as biodiesel. However ethanol has other benefits such as the fact that its combustion products do not contribute to acid rain at all.
C2H5OH + 3O2 -> 2CO2 + 3H2O
You can see the molar ratio here is 5:4 or 1.25.
Methanol is very similar and comes from similar sources:
CH3OH + (3/2)O2 -> CO2 + 2H2O
The molar ratio here is 3:2.5 or 1.2.
Pure Octane is not available as a fuel source but is expressed here for comparison only:
C8H18 + (13.5)O2 -> 8CO2 + 9H2O
The expansion ratio is 17:14.5 or 1.1724
Hydrogen is a highly researched alternative energy carrier because it has no Carbon in it and therefore does not produce carbon dioxide:
2H2 + O2 -> 2H2O
You will notice that the molar ratio is 2:3 here or 0.667... Hydrogen does not explode when combusted but actually implodes. This is not commonly understood. The mechanical expansion during combustion is totally independent of energy release or absorption. The combustion of Hydrogen produces heat and also implodes. The other fuels/energy carriers listed above all produce heat and explode. Hydrogen is an energy carrier totally unsuited to an internal combustion engine.
Fuel Source / Power / Drivetrain / Steering
For my fuel I have selected biodiesel. This fuel takes approximately a 1/4 to 1/3 of the energy it contains to produce.
This vehicle has only one fuel but contains two engines. One engine is a small compression engine in the style of traditional internal combustion engines. I expect an engine in the 100-500 CC range in size. The difference comes in how this engine is cooled. Instead of being cooled into the environment, the heat is used to power a heat engine, such as a small steam engine or turbine. This raises various issues which I believe that I can answer.
One is that water/steam is not used in the heat engine. It uses an organic compound instead which is circulated in a closed system. There are multiple reasons for this. One is that the selected compound can have different physical characteristics than water. A boiling point of approximately 60'C is good because temperatures are almost always less than that (else we would die) yet it takes little heat to cause it to evaporate. The vapour can then be recycled through a familiar looking radiator to be condensed into a liquid, which then is recycled into the heat engine.
Each of these engines is used to turn a driveshaft. These shafts are not connected to the wheels, however, through any sort of mechanical linkage. Any mechanical attempt to integrate the two would likely result in twisted metal and failure - a good reason it has not been used previously. Instead, these two engines turn generators (an electric motor running in reverse) to convert the mechanical energy to electrical energy at a high efficiency (perhaps 98%). This electrical energy has to be stored in a buffer zone.
This buffer zone could be a bank of super-capacitors. This is an area of research that is filled with activity - and success. Even if our current super-capacitor capability is slightly lacking my proposed use, I belief that we shall soon see super-capacitors suitable to this purpose.
Energy is continually drawn from the super-capacitor bank to drive electric motors individually attached to each wheel. It is possible to build a chassis which has room for an electric motor to be attached to each wheel and to rotate with the wheel as it turns. This allows each tire to have independent suspension, turning, and drive.
My proposed method for steering this versatile vehicle is a pair of joysticks, one for each hand. Simpler methods, or ones which utilize the feet, can be implemented, especially for vehicles which limit drive or steering to two of the four wheels. (Obviously it is not required to have drive or steering on all 4 wheels.)
Discarded Ideas
I have decided against both solar panels and electro-voltaic batteries. The above mentioned vehicle should theoretically be more efficient than both the hybrid cars we have now, and also the car developed at MIT which was covered in solar panels. The reason for this mainly stems from production costs. THe production cost for a Li-ION or Li-Polymer battery can be expressed in terms of energy units. The same goes for solar panels. To my current understanding, solar panels will not return any significant gain in energy over the course of their life beyond the energy cost of making them. In regards to batteries, there is a car, called the Tesla, which currently runs on Li-ion batteries. However the batteries have to be replaced after an estimated 100,000 kms. This is because the batteries are limited to a certain number of charge-discharge cycles before they are dead. Furthermore, Li-ion batteries slowly decrease in the amount of total charge they will hold from the time they are manufactured regardless of use or storage. In contrast to a Li-ion battery 1000 charge/discharge cycles, a super-capacitor can be charged and discharged over 10,000 times, vastly exceeding its energy cost to manufacture. As an aside, Li batteries are explosive and have various problems that are more easily circumvented in capacitors. Both capacitors and electric motors have very long lives that outlast their costs of manufacture.
Fuels
Biodiesel, as mentioned, is a fuel which has a 3:1 ration for energy stored:energy production cost. Biodiesel is different from regular diesel in that it contains little to no sulphur, but contains more nitrogen from the plants. A detailed analysis of this is beyond my scope, but I will briefly remark that Sulphur produces sulphuric acid in the atmosphere and contributes to acid rain. Likewise NOxs are produced from plant sources and contribute to acid rain in the form of nitric acid - small difference. These are long chain organic oils that have a relatively high expansion ratio under combustion.
Ethanol only has a 1.5:1 ratio in regards to energy carried:energy spent. This is obviously not as good as biodiesel. However ethanol has other benefits such as the fact that its combustion products do not contribute to acid rain at all.
C2H5OH + 3O2 -> 2CO2 + 3H2O
You can see the molar ratio here is 5:4 or 1.25.
Methanol is very similar and comes from similar sources:
CH3OH + (3/2)O2 -> CO2 + 2H2O
The molar ratio here is 3:2.5 or 1.2.
Pure Octane is not available as a fuel source but is expressed here for comparison only:
C8H18 + (13.5)O2 -> 8CO2 + 9H2O
The expansion ratio is 17:14.5 or 1.1724
Hydrogen is a highly researched alternative energy carrier because it has no Carbon in it and therefore does not produce carbon dioxide:
2H2 + O2 -> 2H2O
You will notice that the molar ratio is 2:3 here or 0.667... Hydrogen does not explode when combusted but actually implodes. This is not commonly understood. The mechanical expansion during combustion is totally independent of energy release or absorption. The combustion of Hydrogen produces heat and also implodes. The other fuels/energy carriers listed above all produce heat and explode. Hydrogen is an energy carrier totally unsuited to an internal combustion engine.
May 19, 2007
Abandonware Downloads
My favourite abandonware website, Abandonia, is down.
I'm trying to download X-Men: Children of the Atom from http://free-game-downloads.mosw.com/abandonware/.
I'm trying to download X-Men: Children of the Atom from http://free-game-downloads.mosw.com/abandonware/.