Prediction of thermal efficiency in a heat transfer system (e.g. CHP)

摘要

A change in the thermal efficiency or performance of a heat transfer system is measured at over times tA,tB,tC to predict when the system will reach a predetermined limit Treturn and so that maintenance may be carried out or scheduled to avoid the pre-determined limit being reached. The heat transfer system can be a combined heat and power (CHP)unit, and has a valve to control fluid flow through a feedback conduit that allow secondary circuit output fluid to return to a secondary circuit input, to regulate temperature of a primary circuit. The heat source may be an internal combustion engine or a boiler. A control unit for a plurality of CHP units has means for receiving operation data relating to each unit and a central processor.