BuysDB:
I like your concept (+1). In the final version you could choose for a model that has a block usage 0 and uses as much breakables as possible. Secondly you could take a look to your heat exchanger, it isn't doing a very great job at the moment.
I think you could improve the heat exchanger by heating the water under pressure so it will not evaporate inside the heat exchanger itself. When the super heated water leaves the heat exchanger it will turn to steam caused by the lower pressure. And of course you should increase the heat exchanger surface.
gl hf.