Well, it is true that if the only thing needed for the reaction to proceed is to maintain a narrow range of temperatures, say it is between 390C and 400C, which probably aligns with a phase-change in the active material -- then not only can superheated steam provide some cooling but more importantly, the COP should soar!
This is because the "return steam and/or hot water" can be easily mixed into the hot steam by a solenoid controlled valve arrangement so that no additional electricity is required past the first cell. The PLC can control only the mixing valves, instead of lossy heaters. This makes the report of "limiting COP to 8", which apparently was translated from the Italian forum, most likely a mistake. Preposterous really, unless it only applies to the first cell in a cascade, which may be the case. That cell is all important. Think about it this way. You have one key cell in the cascade - and it is constructed with elaborate computer controls and thermistors, but the steam from it then feeds two adjoining cells and those two feed the next four, then eight, 16, in each cascade; and maybe you have 4 cascades of 5 stages each. None of the later cells in the cascade need any electrical input at all - except for a valve-control arrangement so that temperature is a function of incoming steam mixed with the colder flow of return hot water. This is actually a lot simpler to do than it sounds. All of the dependent stages essentially are heated by the preceding stage. But the first cell is the only one that gets electrical power, and the heat range for the others is controlled by the steam from the previous bank, by admixing hot water from a return line. The output power comes from only the last stage in the cascade. This is overly simplified, of course, but given that electrical input is only needed for the first cell of the cascade, the gain in COP should be very high, no? -----Original Message----- From: Roarty, Francis X Even if it isn't a start up issue there is a certain ambiguity to threshold temperatures with catalyzed gases where even superheated steam can still provide cooling. -----Original Message----- From: Terry Blanton > The reason given was risk of thermal runaway. If thermal runaway is only a startup issue, cascaded cells might not be an issue.
