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#2
Listeroid/Petteroid/Clones / Re: engine cooling expansion tank connection.
December 08, 2012, 06:01:44 PM
Hi All,
I apologize for not replying sooner, work and family keep a variety of things to do in life that can not be denied.
Romnar,
I find your analysis very revealing and ripe with opportunity for optimizations.
I wish I could move the heat exchanger closer and am thinking of ways to do so. Due to space , building code compliance, neighbor relations and their prolific expectations, and environmental constraints, doing so and maintaining the height for thermal syphoning of both the primary and secondary side of the heat exchanger is a challenge.
I do have a taco pump which can pull the water from the top of the secondary top side heat exchanger and storage tank which circulates the water to the water heater and furnace heat exchangers. The return line of the taco circulation pump is at the bottom of the storage tank. The distance between the heat exchanger and storage tank is 4 inches with a height difference of 4 inches. Thermal syphoning seems to works well here based on the fact that I can run the engine 5 or 6 hours before the bottom of the cooling storage tank reaches 120 F and feel I have to shut down or remove heat from the storage tank.
The primary side coolant capacity is just less than 4 gallons based on when I initially fill the system after tear downs. If I increase the volume of the primary side cooling system, say another gallon, will the hot water be pushed enough through the engine, effectively increasing flow, to keep the water from boiling? Other than extra stress in the radiator hose, what other problems can I expect when allowing the water to boil in the engine heads? Pressure is reduced almost immediately or shortly thereafter due the expansion tank. The head temperature will be around 212 F if the water is changing between gas and liquid states in a low pressure environment provided there is enough cool water available to maintain system equilibrium. Using the boiling water to pump the water into the heat exchanger seems like a condition to take advantage of if the pressure can be controlled. Could there be problems with head gasket, injection pump, lubrication of valve train, etc. using boiling water in the head?
What should the slope be for thermal syphoning to work correctly? Is there a rule of thumb for 1 inch pipe or hose?
From the spit on the finger sizzle test, the only part of the head that sizzles is the exhaust port and the injection pipe just after the heater and before going into the injector, the IR temperature readings confirm this. Can I assume the boiling is most likely contained to with in the head which means the quantity of water boiling is relatively small compared to the four gallons of coolant?
I am going to remove the thermostats for the next run before the maintenance tear down. Will be looking around for other ways to shorten the horizontal distance.
Tom,
I believe Romnar is right about what is happening and glad we have him as a resource. The volume of expansion that I am seeing doesn't make sense compared to thermal expansion of water Romnar experiences. The casting that connects the two head water inlets or outlets by function on the 12/2, forms a lip of ½ inch or so between the water in the head and the top of the common water fitting on the casting. This ½ inch pocket of water is higher than the water outlet and is not allowed to escape. I don't know if this is common to all 12/2 engines but might explain a small volume of water that could boil given low flow cooling system as my system provides. The IR temperature readings at output of engine are 200 to 220F with 205 to 210 being typical readings. I'm looking for picture since I tore it down for maintenance. Whenever I do, brain starts racing of how to improve the system to a achieve an autonomous power plant.
Bob,
The circulation pump effectively does work as you describe but with a delay of the top of the cooling tower providing a buffer to incorporate some hysteresis. An interesting way to look at how the cooling system works and how to maintain system temperature. The thermostats would really only allow the engine to warm faster. If the engine is creating boiling water anyway due to lack of flow, thermostats are redundant and actually hinder the pumping action of the water/gas transitions cycles.
Thanks again for all comments and valuable insights.
Sara
I apologize for not replying sooner, work and family keep a variety of things to do in life that can not be denied.
Romnar,
I find your analysis very revealing and ripe with opportunity for optimizations.
I wish I could move the heat exchanger closer and am thinking of ways to do so. Due to space , building code compliance, neighbor relations and their prolific expectations, and environmental constraints, doing so and maintaining the height for thermal syphoning of both the primary and secondary side of the heat exchanger is a challenge.
I do have a taco pump which can pull the water from the top of the secondary top side heat exchanger and storage tank which circulates the water to the water heater and furnace heat exchangers. The return line of the taco circulation pump is at the bottom of the storage tank. The distance between the heat exchanger and storage tank is 4 inches with a height difference of 4 inches. Thermal syphoning seems to works well here based on the fact that I can run the engine 5 or 6 hours before the bottom of the cooling storage tank reaches 120 F and feel I have to shut down or remove heat from the storage tank.
The primary side coolant capacity is just less than 4 gallons based on when I initially fill the system after tear downs. If I increase the volume of the primary side cooling system, say another gallon, will the hot water be pushed enough through the engine, effectively increasing flow, to keep the water from boiling? Other than extra stress in the radiator hose, what other problems can I expect when allowing the water to boil in the engine heads? Pressure is reduced almost immediately or shortly thereafter due the expansion tank. The head temperature will be around 212 F if the water is changing between gas and liquid states in a low pressure environment provided there is enough cool water available to maintain system equilibrium. Using the boiling water to pump the water into the heat exchanger seems like a condition to take advantage of if the pressure can be controlled. Could there be problems with head gasket, injection pump, lubrication of valve train, etc. using boiling water in the head?
What should the slope be for thermal syphoning to work correctly? Is there a rule of thumb for 1 inch pipe or hose?
From the spit on the finger sizzle test, the only part of the head that sizzles is the exhaust port and the injection pipe just after the heater and before going into the injector, the IR temperature readings confirm this. Can I assume the boiling is most likely contained to with in the head which means the quantity of water boiling is relatively small compared to the four gallons of coolant?
I am going to remove the thermostats for the next run before the maintenance tear down. Will be looking around for other ways to shorten the horizontal distance.
Tom,
I believe Romnar is right about what is happening and glad we have him as a resource. The volume of expansion that I am seeing doesn't make sense compared to thermal expansion of water Romnar experiences. The casting that connects the two head water inlets or outlets by function on the 12/2, forms a lip of ½ inch or so between the water in the head and the top of the common water fitting on the casting. This ½ inch pocket of water is higher than the water outlet and is not allowed to escape. I don't know if this is common to all 12/2 engines but might explain a small volume of water that could boil given low flow cooling system as my system provides. The IR temperature readings at output of engine are 200 to 220F with 205 to 210 being typical readings. I'm looking for picture since I tore it down for maintenance. Whenever I do, brain starts racing of how to improve the system to a achieve an autonomous power plant.
Bob,
The circulation pump effectively does work as you describe but with a delay of the top of the cooling tower providing a buffer to incorporate some hysteresis. An interesting way to look at how the cooling system works and how to maintain system temperature. The thermostats would really only allow the engine to warm faster. If the engine is creating boiling water anyway due to lack of flow, thermostats are redundant and actually hinder the pumping action of the water/gas transitions cycles.
Thanks again for all comments and valuable insights.
Sara
#3
Listeroid/Petteroid/Clones / Re: engine cooling expansion tank connection.
December 05, 2012, 04:51:48 AM
Hi Romnar
Thank you for the reply.
"Can you provide some more info on your setup? You said the rise is 18" from head to top of heatex. How far of a horizontal run? What type and size heatexchanger are you runing?"
The heat exchanger it self is 20" tall by 4" in diameter with two 3/4 inch fittings coming out of the top and bottom for primary and secondary connections. With the pipe fitting to adapt to 1" fittings, the total height is just over 24" tall. The heatex came from a company that made silver reclamation equipment for a no defunct silver halide industry in Rochester area. The unit was brand new and custom made in Spain. There is a 3" by 18" pipe that was supposed to be for filling and expansion on top of the primary input of the heat exchanger. The filling part works great, the expansion part not so well. I had to add a car expansion tank from a Kai or Spirit I believe. Amazing the amount water will expand when heated. I should have calculated that.
The rise is closer to 14 inches due the addition of the anti vibration mats to keep the neighbors happy. The horizontal run is almost 4 feet and appears to work pretty well. The heatex input temperature is around 200-220 F, output temperature is around 80 to 90 F. The secondary output is around 190F with an input (guessing, just warm) 60 to 80 F depending on how long the engine has been running.
The rushing appears to come from when the thermostats open and close, which operate independently. The amount of rushing is dependent on whether the thermostats are in or out of phase in operation. I don't have the measured period between rushing or the time between min and max rushing operation. I would think this would change depending in load. the estimated time between expansion and contraction is 5 minutes with the duty cycle around 40% for heat portion.
After reading my description and your experience, I have a restricted primary side or I need better thermostats? I would prefer to keep the thermostats since I use a coaxial fuel heating system in the upper hose. (more questions) The outer diameter of the fuel line that runs inside the 1" ID hose is 1/4" in diameter. I have restricted the primary side to much?
Just to add more complexity to the mix and to change my analysis a little. I was amazed by how much smother the engine ran on WVO than on Diesel. I also have the carbon build up that others have mentioned which required a tear down every month to month and a half to remove the carbon when running 24/7. I also had more condensation in the exhaust when running WVO than Diesel. Get ready to cringe, I adjusted the injection timing on both cylinders from the 18 degrees traditional setting to 22 degrees in 1 degree steps to see if I could get the engine to perform as well as on diesel. Meaning, have same punch on each power stroke as when using diesel fuel. As it turns out, at 23 degrees just knocks like crazy and 22 degrees runs like using diesel but using WVO.
There are some problems running at 22 degrees injection timing, starting on Diesel causes the engine to knock. I start on diesel just to get it running on a cold start and quickly change over to WVO. The other problem is, I don't create as much heat out of the engine to heat my house which brought me to the question of moving the expansion tank connection placement.
I hear more questions. The good side of 22degrees injection timing is increased power, 1/3 less fuel usage for same load, much less condensation ( have not figured why out yet) and the holey grail, tear downs due to carbon are 3 months instead of a month. Some of the carbon reduction could be due to the modified exhaust the uses venturii effect to suck the air out of the non firing cylinder that got changed at the same time. (I know, only change one thing at a time.) Oh, the other good/bad effect is I have to hurry along with maintenance so I don't have to start on diesel.
Even with the reduced heat, there still is water expansion as before and the water temperatures are about the same as before, expansion cycle times are longer come to think of it. Will measure expansion cycle period when I put the engine back together. The amount of heat that I can pull out of the secondary cooling 55 gallon drum is about half based on how often the circulation pump needs to turn on. FYI, The circulation pump pulls hot water out of the drum when top 3/4 of the drum gets to 180F and dumps the heat into the water tank(another heat exchanger) and furnace radiator coil. A simple push system that sends heat whether you need it or not. The furnace heat get connected to the pool pump heat exchanger in the summer. It's amazing what you can do with garden hoses. I'm glad my significant other doesn't venture into the basement.
Now that you the full story, what do you think?
Sara
Thank you for the reply.
"Can you provide some more info on your setup? You said the rise is 18" from head to top of heatex. How far of a horizontal run? What type and size heatexchanger are you runing?"
The heat exchanger it self is 20" tall by 4" in diameter with two 3/4 inch fittings coming out of the top and bottom for primary and secondary connections. With the pipe fitting to adapt to 1" fittings, the total height is just over 24" tall. The heatex came from a company that made silver reclamation equipment for a no defunct silver halide industry in Rochester area. The unit was brand new and custom made in Spain. There is a 3" by 18" pipe that was supposed to be for filling and expansion on top of the primary input of the heat exchanger. The filling part works great, the expansion part not so well. I had to add a car expansion tank from a Kai or Spirit I believe. Amazing the amount water will expand when heated. I should have calculated that.
The rise is closer to 14 inches due the addition of the anti vibration mats to keep the neighbors happy. The horizontal run is almost 4 feet and appears to work pretty well. The heatex input temperature is around 200-220 F, output temperature is around 80 to 90 F. The secondary output is around 190F with an input (guessing, just warm) 60 to 80 F depending on how long the engine has been running.
The rushing appears to come from when the thermostats open and close, which operate independently. The amount of rushing is dependent on whether the thermostats are in or out of phase in operation. I don't have the measured period between rushing or the time between min and max rushing operation. I would think this would change depending in load. the estimated time between expansion and contraction is 5 minutes with the duty cycle around 40% for heat portion.
After reading my description and your experience, I have a restricted primary side or I need better thermostats? I would prefer to keep the thermostats since I use a coaxial fuel heating system in the upper hose. (more questions) The outer diameter of the fuel line that runs inside the 1" ID hose is 1/4" in diameter. I have restricted the primary side to much?
Just to add more complexity to the mix and to change my analysis a little. I was amazed by how much smother the engine ran on WVO than on Diesel. I also have the carbon build up that others have mentioned which required a tear down every month to month and a half to remove the carbon when running 24/7. I also had more condensation in the exhaust when running WVO than Diesel. Get ready to cringe, I adjusted the injection timing on both cylinders from the 18 degrees traditional setting to 22 degrees in 1 degree steps to see if I could get the engine to perform as well as on diesel. Meaning, have same punch on each power stroke as when using diesel fuel. As it turns out, at 23 degrees just knocks like crazy and 22 degrees runs like using diesel but using WVO.
There are some problems running at 22 degrees injection timing, starting on Diesel causes the engine to knock. I start on diesel just to get it running on a cold start and quickly change over to WVO. The other problem is, I don't create as much heat out of the engine to heat my house which brought me to the question of moving the expansion tank connection placement.
I hear more questions. The good side of 22degrees injection timing is increased power, 1/3 less fuel usage for same load, much less condensation ( have not figured why out yet) and the holey grail, tear downs due to carbon are 3 months instead of a month. Some of the carbon reduction could be due to the modified exhaust the uses venturii effect to suck the air out of the non firing cylinder that got changed at the same time. (I know, only change one thing at a time.) Oh, the other good/bad effect is I have to hurry along with maintenance so I don't have to start on diesel.
Even with the reduced heat, there still is water expansion as before and the water temperatures are about the same as before, expansion cycle times are longer come to think of it. Will measure expansion cycle period when I put the engine back together. The amount of heat that I can pull out of the secondary cooling 55 gallon drum is about half based on how often the circulation pump needs to turn on. FYI, The circulation pump pulls hot water out of the drum when top 3/4 of the drum gets to 180F and dumps the heat into the water tank(another heat exchanger) and furnace radiator coil. A simple push system that sends heat whether you need it or not. The furnace heat get connected to the pool pump heat exchanger in the summer. It's amazing what you can do with garden hoses. I'm glad my significant other doesn't venture into the basement.
Now that you the full story, what do you think?
Sara
#4
Listeroid/Petteroid/Clones / engine cooling expansion tank connection.
December 03, 2012, 01:16:27 PM
Hi All,
I want to increase the efficiency of the cooling system and reduce the amount of water vapor from the expansion tank.
Back round info: I have 12/2 Lister that is cooled with a heat exchanger using the typical thermal siphon setup. There are 190 F thermostats for each cylinder head, with 3/16 bypass holes to let the air thru. There is an expansion tank connected to the top of the heat exchanger similar to every one Else's it seams. When the thermostats open up, a rush of hot water expands into the tank then gets sucked back into the engine and heat exchanger when the water cools. There is 1" hose from the engine to the heat exchanger with a rise of 1.5 feet. The return line from the heat exchanger to the engine is just above level with the same type 1" radiator hose. The best I could do with the room I have and the size of the heat exchanger, system works well.
Question:
What would be the problem if the expansion tank was connected to the cold engine side of the heat exchanger and have a valve at the engine hot side of the heat exchanger to let the air out? The expansion tank would still need to be the same height to ensure the system is filled with water.
Has this ever been done before and what where the problems?
Why would you want to do this? More of the hot water would get pushed through heat exchanger to be cooled by the secondary storage tank water and maybe capture more heat. There would be less water vapor into the air and still keep the pressure in the primary side of the cooling system low?
Any all comments welcome, further explanations gladly given.
Sara
I want to increase the efficiency of the cooling system and reduce the amount of water vapor from the expansion tank.
Back round info: I have 12/2 Lister that is cooled with a heat exchanger using the typical thermal siphon setup. There are 190 F thermostats for each cylinder head, with 3/16 bypass holes to let the air thru. There is an expansion tank connected to the top of the heat exchanger similar to every one Else's it seams. When the thermostats open up, a rush of hot water expands into the tank then gets sucked back into the engine and heat exchanger when the water cools. There is 1" hose from the engine to the heat exchanger with a rise of 1.5 feet. The return line from the heat exchanger to the engine is just above level with the same type 1" radiator hose. The best I could do with the room I have and the size of the heat exchanger, system works well.
Question:
What would be the problem if the expansion tank was connected to the cold engine side of the heat exchanger and have a valve at the engine hot side of the heat exchanger to let the air out? The expansion tank would still need to be the same height to ensure the system is filled with water.
Has this ever been done before and what where the problems?
Why would you want to do this? More of the hot water would get pushed through heat exchanger to be cooled by the secondary storage tank water and maybe capture more heat. There would be less water vapor into the air and still keep the pressure in the primary side of the cooling system low?
Any all comments welcome, further explanations gladly given.
Sara
#6
Listeroid/Petteroid/Clones / Re: Camshaft
June 21, 2011, 04:03:51 AM
Any status updates as of late? Thank you for all the work and time to solve this problem.
Sara
Sara
#7
ST and STC generators / Re: ST heads for battery bank charging
March 08, 2010, 07:36:41 AM
Hi
It is interesting that the required field winding voltage is lower than the desired output voltage from the main ST generator windings. Using a standard B type heavy duty external voltage regulator for a car alternator should work great. Most of the automotive solid state voltage regulators have current limit on the field driver and over voltage protection on the alternator output, There is less chance for the ST head to burn up. I could be wrong, all comments welcome. You couls use an A type alternator regulator, The B version is what I have on hand.
What to do:
1) Rectify the output of the ST generator with a 10O amp or more full wave bridge rectifier. These devices have a large metal plate that needs to be attached something that stays cool like a heat sink or the air cooled stator housing. The current rating was figured by taking the power rating of the ST head and dividing by 120Vrms and multiplying by a safety factor of 1.5, picking the next higher available current rating. Don't forget the fuse or circuit breaker rated for voltage and current you plan to run. If you have a 12KWatt ST generator, 12KW/120Vrms equals 100Amps available current to charge with. Since it is desired for the fuse to blow before head, Pick 60 amp fuse or circuit breaker
2) Clean up the rectified DC with Electrolytic capacitors with a voltage rating of atleast 1.5 times your intended output voltage and as much capacitance as possible to get rid of the pulsating current. If you plan to switch between 28 volt DC and 120 or 240 VAC using a switch, Make sure to disconnect the rectifier and capacitor bank if the capacitor voltage rating is less than 200volts. ( this would be fun to watch, similar to your car bursting into flames and then having to replace it)
3) Using the B type regulator, Connect one side of the ST field winding to the negative side of the rectified DC output. Connect the positive side of the rectified DC to the alternator output terminal and ignition switch terminals of the voltage regulator. Connect the the unused ST field winding to the field terminal of the voltage regulator. Use of a fuse in series with the filed lead is a good measure of saftery.
4) The harmonic windings is not used and secured appropriately
5) Connecting a battery bank to the rectified output of the ST Generator paying attention to polarity.
Placing a switch in series with the ignition terminal can be used to disable the generator output( more or less) and reduce current draw when engine is not running.
What did I miss or should be concerned with? I would suggest running the ST head at rated speed to ensure cooling of both the head and rectifier module.
Which do you think would last longer, an ST head or a high output heavy duty alternator?
Sara
It is interesting that the required field winding voltage is lower than the desired output voltage from the main ST generator windings. Using a standard B type heavy duty external voltage regulator for a car alternator should work great. Most of the automotive solid state voltage regulators have current limit on the field driver and over voltage protection on the alternator output, There is less chance for the ST head to burn up. I could be wrong, all comments welcome. You couls use an A type alternator regulator, The B version is what I have on hand.
What to do:
1) Rectify the output of the ST generator with a 10O amp or more full wave bridge rectifier. These devices have a large metal plate that needs to be attached something that stays cool like a heat sink or the air cooled stator housing. The current rating was figured by taking the power rating of the ST head and dividing by 120Vrms and multiplying by a safety factor of 1.5, picking the next higher available current rating. Don't forget the fuse or circuit breaker rated for voltage and current you plan to run. If you have a 12KWatt ST generator, 12KW/120Vrms equals 100Amps available current to charge with. Since it is desired for the fuse to blow before head, Pick 60 amp fuse or circuit breaker
2) Clean up the rectified DC with Electrolytic capacitors with a voltage rating of atleast 1.5 times your intended output voltage and as much capacitance as possible to get rid of the pulsating current. If you plan to switch between 28 volt DC and 120 or 240 VAC using a switch, Make sure to disconnect the rectifier and capacitor bank if the capacitor voltage rating is less than 200volts. ( this would be fun to watch, similar to your car bursting into flames and then having to replace it)
3) Using the B type regulator, Connect one side of the ST field winding to the negative side of the rectified DC output. Connect the positive side of the rectified DC to the alternator output terminal and ignition switch terminals of the voltage regulator. Connect the the unused ST field winding to the field terminal of the voltage regulator. Use of a fuse in series with the filed lead is a good measure of saftery.
4) The harmonic windings is not used and secured appropriately
5) Connecting a battery bank to the rectified output of the ST Generator paying attention to polarity.
Placing a switch in series with the ignition terminal can be used to disable the generator output( more or less) and reduce current draw when engine is not running.
What did I miss or should be concerned with? I would suggest running the ST head at rated speed to ensure cooling of both the head and rectifier module.
Which do you think would last longer, an ST head or a high output heavy duty alternator?
Sara
#8
Listeroid/Petteroid/Clones / Re: Thanks, Jens!
September 26, 2009, 05:22:48 AM
Thank you for taking the time to continue on a great place to spend some time and learn about this great hobby.
THANK YOU
Sara
THANK YOU Sara
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