PERFORMANCE OF COGENERATION SYSTEMS USING WASTE HEAT

The performance of two systems using a low-temperature heat source (100 and 125 degrees C) and an ORC with R245fa as the working fluid for combined heat and power production has been modeled. The first system supplies the heating load with a heat exchanger in series with the ORC boiler. In the second one this function is fulfilled by the ORC condenser. The results show that the effects of the heating load on the performance of the two systems are very different. The net power output decreases monotonically with increasing heating load for the first system while it exhibits a maximum in the case of the second one. The impact of the heating load and the source temperature on the turbine size, on the total thermal conductance of the heat exchangers, on the total exergy destruction and on several other parameters is also presented and discussed.