4 ms·
Per https://www.ianvisits.co.uk/blog/2017/06/10/cooling-the-tube-engineering-heat-out-of-the-underground/ https://www.ianvisits.co.uk/blog/2017/06/10/cooling-th
by zkms 9y ago
Per https://www.ianvisits.co.uk/blog/2017/06/10/cooling-the-tube-engineering-heat-out-of-the-underground/ https://www.ianvisits.co.uk/blog/2017/06/10/cooling-the-tube... there already is regenerative braking on some cars, the issue is that regenerative braking can't happen if there's no train on the same section of DC bus that can accept the power. There needs to be some sort of inverter to sink the higher DC voltage and send it back into the grid.
- Shivetya 9y agowhy not incorporate storage in the car and discharge it when launching from a stop. I am sure there has to be a little onboard storage but it appears they need more if they cannot discharge it. Isn't this ideal for ultra capacitors? it really reads like the cars must be changed to fix the problem as they are the heat source. so unless an economical means can be found to store/discharge it between stations their only solution is to cool the tube itself. So isolate the passenger area from the tube area at all stations and force cool air from points where you have easy access to cooling. the air flow would of course move in the direction of trains. can that work?
- Symbiote 9y agoAdding stuff to trains ("cars"?) increases the weight, which means more energy is needed to move the thing. It also takes up space, which is very limited. Some storage system near a station (where there is more ventilation) could make sense, but probably costs more than the system mentioned in the IanVisits blog to return power to the city (i.e. convert the DC the trains use back to AC for the city). I don't think the isolation idea would work. Where does the air for people on trains to breath come from?
- robryk 9y agoOr you can just convert that energy into heat, but do that on the surface. Have large resistor banks on the surface that you connect to the DC grid when the voltage is too high.
- raverbashing 9y agoThat would be acceptable 100 years ago. Not today
- jrockway 9y agoWhy? Stopping the trains wastes energy regardless of whether you dump the extra power into the wheels with friction brakes or into a resistor bank. Dynamic brakes on diesel trains already sink the power into resistors.
- robryk 9y agoWhy is moving the place one dumps heat from below ground to above ground not acceptable?
- raverbashing 9y agoBecause you can use it for something else other than heating, like, putting it back into the grid, storing (either battery, flywheel or supercapacitor).
- hydrogen18 9y agoThat would work, but a large flywheel would also be a good solution. You could spin up the flywheel to store energy and if it reaches maximum speed then use the resistors. You'd also need to detect load on the grid and then run the flywheel system in reverse to assist vehicles that are moving.
- deleted 9y ago[deleted]