openspaceman

it's been nigh on fifty years since I did any courses on electrical engineering but it depends what type of generation you are meaning, as I said the average losses between generator and consumer are 7+%. Most coal fired station back then were high temperature steam turbines and managed a bit less than 40% but the generators had low operating and maintenance costs. Some standby plants were diesel and had better thermal conversion efficiency but high O&M costs, then there were peaking plants which cost a fortune to run, often open cycle gas turbines based on early jet engines, at a time when the consumer paid 7p/kWh these cost about 50p/kWh to run. When the internal fire museum acquired one of these after 30 years in service, from Princetown IIRC, it had only a few hundred hours on the clock. Nowadays the best combined cycle gas turbine sets, which supply the bulk of our fossil fueled power manage just short of 60% thermal conversion efficiency. We still get about 15% of our power from our nuclear power (plus quite a lot we import from France which is mostly nuclear powered) and these have a lower thermal conversion efficiency than coal fired as the boilers are run more conservatively . That's a marketing thing, power generators pay way less for gas then we do and most of their costs are in sales and distribution. I currently pay about a quarter of the price of a kWh of electricity for my gas but they do different jobs.

It's a simple economic proposition, if the dried wood attains a higher price in the market place than the cost of the drying, the heat source is immaterial. Anyway the waste from a logging operation probably amounts to over 5% of the raw material so burning it for a kiln makes sense. Actually about 15 years ago a government agency was burning gasoil to dry wood for Tilbury power station in order to get renewable Obligation Certificates and that was naughty. I wonder how much sawnwood kilning requires in the scheme of things, obviously I think it should be done with sawmill waste. It's a bit of a no brainer but there's good reason to use waste wood at the point of production in any case where its heat can be used. I agree with the first part and think I can answer the second; power loss in the grid and distribution runs at about 7.7% but this shouldn't impact any consumer as the voltage will be maintained at the substation, any circuits further from the substation will tap the transformer at a higher voltage to make up for losses.

I'd need to see some figures for particulates per MJ of heat at various power settings released before I'd accept there were benefits in wood this dry. From what I remember wood at 12% mc wwb can be burned the cleanest but it's not BATNEEC

I'm sure it is and equally sure it stems from use of high moisture content wood and the habit of turning down the fire to "keep it in".

Firstly I am a fan of using the natural drying processes, especially making use of the greenhouse effect of a transparent kiln but I did conceptualise a high temperature kiln which we built for a supplier of firewood. I still think this is a way forward but making more use of waste heat. Not necessarily, and as has been pointed out we use little coal for electricity. the effluent from a coal plant can be cleaned and because it is running constantly the thermal conversion efficiency is optimised. When the electricity is used to charge a battery and then discharged to drive a car's motor I guess the conversion from power station to wheel is around 70% and is fairly constant. Whereas a IC engined car is operating at lower efficiency overall unless at constant speed.

I was thinking more of IBC crates or potato boxes, I have no experience myself as I cut split and stack mine by hand for my own use and seem to have no problem getting them dry enough in a summer season. When I sold logs 30 years ago they were nowhere near 20% but then it was common to see a wisp of blue smoke from chimneys, a lot has changed in pollution awareness since.

Ok but for extraction 2-3m is better so an extra cross cutting will be needed another operation and another Easily enough over a summer to get dry, much better if under a roof, in sections as small as that, not so in the round. Another operation How does that compare labour wise to processing freshly harvested wood to size and dumping it into ventilated containers in one hit, moving under a roof, preferably transparent, and then taking them from store and delivering them in one hit?

The quote @Paul in the woods gave shows the reasoning. I have mentioned it before in relation to how moisture meters are calibrated. @Stere I don't know but have always suspected they are calibrated on a dry weight basis, I don't have one but I suppose I should get one to check. In practice the dryer the wood is the nearer they get to the same reading. @Woodworks the page you quoted has this example "(For example, if a piece of wood weighing 100 kg contains 50 kg of water, the moisture percentage is then 100%)". The calculation of 50kg moisture divided by 50kg of oven dry weight giving 100% mc shows they are using a dry weight basis, it would be 50% on a wet weight basis.

I'm glad you found that, it confirms that the equilibrium moisture content tables you are reading are based on the moisture content on a dry weight basis so if we take as an example for you of 90% RH and 10 degrees C from your chart that gives an equilibrium moisture content of ~23% dry weight basis, which is a moisture content of 18.7 on a wet weight basis, quite a bit under the 20% target.

it's a variation of Parkinson's law which says work expands to fill the time available, in the same way if you fit a bigger bookshelf you will buy more books. I saw this when I started driving, many folk still had no cars and the local factory workers mostly bussed, walked or cycled to work. Once cars were common people would compete for work further than 5 miles or so, then the M25 was built and it became feasible to commute a few towns away, so my schoolmate took a job in East Grinstead which had been a 2 hour trek but was now 55 minutes and it was his time (and higher pay) which were the considerations rather than fuel consumption.

What worries me about this chart is that woodworkers and joiners generally use moisture content referenced to the dry weight of wood, for burning we usually reference the wet weight of wood and I cannot see on this site which moisture content they are using. So for instance if we have a mass of wood which consists of 20kg of water and 80kg of oven dry wood then a joiner might say that's 20/80=25% mc dry weight basis whereas I would say that's 20/100=20% mc wet weight basis. Also there is a hysteresis so as a log regains moisture content at a given RH and temperature it tends to maintain a lower moisture content than the same wood being dried in the same conditions. It is of course in the ballpark of gnat's piss but laws do need to be precise. BTW does anyone know how this 2m3 is defined, is it a bulk load or solid wood?

The equilibrium moisture content is lower in the SE of England. Beau's Dartmoor is a humid place which is why he struggles to keep seasoned logs below 20% because even under covered storage they can pick up moisture from the air. I don't think this legislation is police-able so it will come down to customer relations, it will be an upset customer that triggers an investigation by trading standards.

Yes. It's been a long time since I was in Belgium but all the rural houses had stacks of freshly felled logs drying under the eaves ready for the winter. UK seems to have lost a woodburning culture during the industrial revolution when coal became plentiful. Not many UK homes have the luxury of space to season wood and those that do tend to be owned by people who prefer to spend money on more convenient heating. Of course domestic wood burning for heat as opposed to luxury is a minority undertaking and insignificant in the scheme of energy consumption but it has its place in making use of what else would be a waste.

That makes more sense to me than replacing a firebrick in the combustion chamber with a boiler tank. The reason for insulating firebricks is to keep the combustion hot enough to complete inside the firebox. Sticking a cold surface in there defeats this. Far better to remove heat above the firebox after combustion has completed. The concept of quenching a burn before completion is easily demonstrated with a metal spoon and a candle.

This is my understanding I carry a multitool with two 1 1/2" blades on my belt most of the time and keep a locknife in my lunchbag, which I only take out if I am working or volunteering As a retired person other than on you own land, I doubt it.

Yes it could be a jammed relief valve or even a constricted return line but also consider that the bigger 3p pumps have a lower safe working pressure once you get above about 80ml/revolution which is why if you need to maintain 200bar and 100lite/min at 1500rpm you are better off with tandem 2p series.

I wouldn't be surprised if it has a TPO as it looks a fine tree.

Though it pains me to say it I agree with you, I felt the same about the sale of council housing, a big mistake for the country but I would have bought had I been a tenant.

I cannot see a thorn amongst them ;-), I'd call it a clump

I don't think this HS2 project has been well managed and I cannot see why it will be so expensive. Does anyone know how the projected costs are attributed between compensation, land purchase and civils/engineering work? I grew up in the age of the car and tend to use mine for all my travelling so I do not understand how people use the rail services but I do realise a lot of people in cities don't own cars and rely on public transport and taxis. Anyway one of the things it is supposed to address does include reopening some old lines and stations but this cannot be done while the current main lines share tracks with local traffic. There are often simply not enough time slots to fit extra traffic from old lines to run onto the existing network. Consider also that trains have to be separated by 15 minutes, so one 125mph train occupies a lot more track than a commuter train running at 45 mph. Taking high speed trains off the typical 4 track mainline could double its capacity for stopping trains. Also more lines were closed since 1920 before Beeching than after. Also think about how railways were originally funded, it was not by the government but by entrepreneurs expecting to make a profit from the investment.

Sort of; it makes a cleaner exhaust as less unburnt fuel gets past before the exhaust port closes, combustion takes place after that. Yes and the diesel has the advantage that the fuel is only injected after the inlet and exhaust are closed. With a conventional two stroke the piston descending on the power/exhaust stroke scavenges the fuel-oil mix from the crankcase and pushes it up the transfer port into the cylinder. some goes directly through the exhaust port. What the stratified porting aims to do is allow neat air directly, under the piston, through the new ports in the cylinder and into the transfer ports without going into the crankcase. Then as the piston descends this neat air is the first into the cylinder followed by the fuel and air from the crankcase.

It's against the trade's code of practice to repair or re end hoses so very unlikely to get it done. I too found them the best solution as carrying a pipe "crimper" around was not possible. I kept an ammo box of various sizes and ends, I even brazed some special ones on the spot to get a haulier out of trouble. Again these reusable fittings are deprecated by the trade's COP so tend to be strictly DIY. My ammo box with fitting was "mislaid" by a fitter at my old work so recommendations for a supplier needed as I get my old machines up together. I originally used a 7V angle grinder which just about had the energy to make a cut either side of a burst, how things have changes with a Li-ion powered angle grinder running for many times longer nowadays. Later I carried a cheap 900W generator for such work.

Many new stove installations into what was an open fireplace use a flexible flue liner which is then back filled with a bulk insulating material, like perlite or vermiculite. This keeps the column of exhaust gases rising up the chimney hot. This is done mostly to prevent condensates from forming and running back down. You can see the effect in some old houses where a coal fire has been replaced by a wood stove and the thing has been left smouldering , often with damp wood being used. The line of the flue is marked by a black patch where the pyroligneous acidic condensate has seeped through the brickwork, often damaging the mortar. If you have a decent masonry flue then you can have good resistance to this happening and the high flue temperature heats the flue and brickwork as the fire is blazing. As the fire burns down to embers the brickwork is still warm and continues giving off this heat to the house. Taken to the extreme is the masonry stove which is charged up with the whole load of logs for the day and fired off flat out for a few hours and then damped down once there is no wood left, the house then heated by the masonry with multiple flue passages. The same concept is used in soapstone stoves. I doubt may existing houses have the space for a masonry stove but some of the principles can be used with a traditional chimney breast. In my 1862 built house I had the chimney relined with cement many years ago, I fire my stove so that there is always a good active flame until only a bed of charcoal remains when I cut the primary air. The whole chimney breast is at blood heat when I retire as is the one in the floor above. This keeps the house warm till morning.

Have you considered using the thermal mass of all the masonry to complement the heating?

Ist picture is exhaust side, then two of inlet. It looks like something has been ingested from the carb and dinged the piston skirt. A modern stratified intake saw and little wear showing. Have you checked the ring gap?