Science266677

Thanks, I have found out the heat capacity of the sludge. it is 3.10. Please can you sense check my calculations below. I am sure they are right. Heat Exchanger 1 Heat Exchanger 2 Hot Water Inlet Temp 68.23 Hot Water Inlet Temp 68.23 Hot Water Outlet Temp 61.49 Hot Water Outlet Temp 60 Sludge Inlet Temp 30.8 Sludge Inlet Temp 30 Sludge Outlet Temp 35.16 Sludge Outlet Temp 36 HW Temp Diff 6.74 HW Temp Diff 8.23 HW Temp Diff 4.36 Sludge Temp Diff 6 Water Water 4.18 kj/Kg 4.18 kj/Kg 92 litres 92 litres 6.74 change 8.23 change 2591.9344 Kj 3164.9288 Kj Sludge Sludge 3.1 kj/Kg 3.1 kj/Kg 100 litres 100 litres 4.36 change 6 change 1351.6 Kj 1860 Kj 52.14638148 EFFICIENCY 58.76909458 EFFICIENCY Water flow rate 30m3/hr or 8.4kg/s Sludge flow rate 30m3/hr or 8.4kg/s

Thanks So if I assume that the sludge has a heat capacity of 3.99 kJ/Kg. How do I do the energy calculations based on my given temperature readings before? Lets say my temperatures were - Input hot water 68C Output hot water 61C Input Sludge 30C Output sludge 36C Hot Water Inlet Temp 68 T1 Hot Water Outlet Temp 61 T2 Sludge Inlet Temp 30 t1 Sludge Outlet Temp 36 t2 Temp 1 32 T1-t2 Temp 2 31 T2-t1 δt 7 T1-T2 This is where I am getting lost!!! Thanks Rob

Hi, I am trying to calculate the heat exchanger efficiency of a system heating a sludge using hot water. The boilers on the system heat the water to a set point of 70C. The water flow is constant because the water is low in solids and the incoming water temperature is read at 68C consistently. I cleaned the heat exchanger today and the sludge was incoming at 30C and outputting at 36C, this varies though from 15C input up to 45C input. It is a spiral heat exchanger. The hot water pump flow rate is 30m3/hr or 8.4kg/s The sludge pump flow is also 30m3/hr or 8.4kg/s (No flow meter fitted but assuming this value today after cleaning not including pump wear) The sludge is contaminated with lots of heavy fibourous solids. The heat exchanger is blocking over time, gradually until it gets so bad the sludge pump blows its mechanical seals. I clean the heat exchanger after about a week to stop the pump damage. As the sludge circuit of the heat exchanger blocks the flow rate decreases and the heat transfered to the sludge drops. The rate of blocking varies between 2 days and one month depending on the upstream sludge processing which impact the sizes of the fibourous solids coming through the exchanger. The temperature readings are measured on screen in and out on both circuits of the heat exchanger. Ideally I would like to have a value I can set myself where I will clean the heat exchanger (maybe when I lose 40% of the transfer efficiency) I know this might be quite simple but my maths isnt all that good to work this out. Thanks for your help in advance, Rob

Yes CERN - It was months ago when I watched it and it was shown in retrospect so I am sure they have tried and retried and got results..... Or not but whatever they found i am intersted.

Hi I watched a programme about the particle accelerator underneath the city of geneva. It was near completion when it was aired. I have searched the internet but cannot find any information on what happened when they ran the machine. Has it been run? Am I in the wrong forum? Rob

Hi I have been researching carbon emissions and have found that they stay in the atmosphere for 70-130 years. Would it be possible to remove this carbon for re use? Has anyone been looking into it? I get all sorts of obscure sites when I try and search for this on the internet mostly returning me back to how past ice ages have ocurred - for example - The Moronic Inferno http://www.bbc.co.uk/dna/h2g2/A26089743 My question is would it be theoretically possible to take back the carbon present in the atmosphere resident for ages to reuse it as a fuel? Thanks Rob

I would like to use Thermopiles to store energy in a cell then run an ultra low wattage bulb from the cell. I would like to supply the thermopiles using the energy from - I2R Heat Losses I have been trying to come up with a way of using the i2r heat losses found in many machinery control centres at industrial installations. The areas around the busbars which supply the energy are hot sometimes very hot and heat the air in the room to above 30 degrees. I don't know if you were to clip something onto the busbars whether or not it would be detrimental for the supply of energy yet but I will investigate. Maybe the heat could be absorbed from the area around the busbars. Pipe Heat Losses I am also interested in using the heat losses from pipes containing a hot liquid. Most purposely heated liquids are insulated to keep heat in. Is this posssible?? Some things I Dont know I dont know the lowest energy using bulbs or how bright or expensive they are. I dont know the input characteristics needed to supply a storage cell used for output to bulb. I dont know the highest or lowest temperatures thermopiles are effective at and Temp vs O/P. I dont know if having a heatproof material attached to the busbars would be detrimental to the transfer of energy to supply the machinery. I dont know where to find information on recent developments relating to thermopile technology. I only know one manuacturer of thermopiles but realise one could be developed. If you have any comments or can help me with any answers to what I don't know that would be really great and thank you. Rob

Hi Does anyone have any resources on fuel cell technology? Can you trickle charge them? Size vs Output capacity? Thanks for your help, Rob

The voltage produced is proportional to the temperature difference between the two junctions. I see that http://www.dself.dsl.pipex.com/MUSEUM/POWER/thermoelectric/thermoelectric.htm and honeywell actually make one. Thanks again

Thanks thats interesting - I searched on google and they seem to be mainly sensors. Do you mean you can adapt the thermocouples to use the heat to give power output? Do you know any sites I can read about it?

Hi I am Rob, Im new to the forum. Please can someone tell me if there is a battery which is powered by heat? I need to take the heat in a pipe and use it to power a pcb. is it possible? Thanks