|
On a "normal" engine, a small extra load has a byproduct of creating a lot higher load on the engine via the alternator. 100w of heating element might make the engine work harder and create 400w more heat in the coolant system, but you're using a ton more fuel. In that case, just driving the vehicle to load the engine would give good results I'd think. If the engine is oversized, the heaters might push the engine in a more efficient load range with the side effect of quicker warmups.
On Diesels, deleting the EGR helps increase MPG, however the EGR cooler should be left in tact for the coolant warmer effect. The actual EGR valve going into the intake is what they should be focusing on and working out a way to either dump the exhaust under the car, or pipe it back into the main exhaust pipe. I haven't done too much thinking on the best way to redirect the flow, and what to do with that flow. It seems some sort of a valve and pushing the exhaust back through the orig muffler would be the most logical setup.
Some cars have the "exhaust manifold" built into the head with a water jacket around it. Effectively it's an EGR cooler purely for heating up the engine coolant faster. It's always active, so the extra heat once fully warmed up has to be expelled via the radiator. I suspect at higher loads, the cooling load would increase quite a bit. Besides that negative, it seems to be all positives to the design, it's probably the most efficient way to recover extra heat from the exhaust system with the least moving parts.
I should probably look more into how the prius system is designed since it's likely sized about right for my engine, the other ones might be a bit too big.
I suspect that system will help a lot for winter driving as well since with the HVAC set to warm it will need to run the engine to generate the heat, so engine off costing will happen less often at those lower speeds. Probably not a huge factor for me since most of my driving is above the EV speed threshold.
I'm starting to wonder if my hybrid battery has a poor charge/discharge efficiency for some reason, or maybe the 12v battery is a solid draw on the system. I suspect since the 12v battery basically does nothing once the car is in ready mode, I could remove the 12v battery once in ready mode and replace it with a capacitor just to smooth out the voltage. One of those 200v caps from a power supply I think would be large enough. It should charge effectively instantly and be more or less 0 draw on the 12v system for charging. This test I have in mind should simulate roughly with a lithium ion battery would be like in the car. Of course when I turn it off it needs more power than what the cap can store to kick on everything. Some jumper cables and leaving the cap always hooked up could be a pretty simple test for the effect on charging that weak battery.
I just checked the battery voltage for giggle, currently sitting at 12.42v. When the car was cleaned it was ran low 11.9v and It has about 5 hours or so of powered on time since then, so it's still charging up, or the battery was charged and the load of the car has drawn it down that low already.
|