Polar Power is the other company but they are using liquid or gas fueled engines though a number of companies are using solar but I’m looking for wood. I don’t think I’m going to find what I want right now so that means modification or wait a couple years.
There seems to be at least four major types of CHP, reciprocating, Sterling, Rankine Cycle (high temp), Organic Rankine Cycle (low temp) and low temperature difference engine. The OCR seems to be fairly common in industries that have burnable waste or create a lot of waste heat. Here is a response I received from Global Microturbine when I asked about using a wood fired boiler to their ORC engine. BTW they responded in an hour.
“Generally, the hotter the water the better. In this case, it would be advantageous to use some type of thermal oil, where you could heat it to a great deal hotter. The reason for such is that it goes through our heat exchanger / evaporator and exits about 70-80 degrees cooler.
In this application, if you could heat the thermal oil to say, 280 deg F, then you could still use the exit for radiant or hot water heating.
For low temperatures, like 180 deg. F, the heat rate is around 40,000 btu / kWe, therefore, you'd need a boiler to produce 1,200,000 btu of hot water (that's about twice as large as the unit you have).
However, if you could use thermal oil, then you might be able to get 20,000 to 30,000 btu/kWe, which gives you more kilowatts.
We have had a few requests for a 10 kw unit, but at this time, we have to go with larger units, just because the smaller ones are too expensive an nobody would buy them.” |