Experimental investigation of the domestic CHP ORC system in transient operating conditions

This article discusses the research conducted on a small CHP ORC system, which has been developed with the aim of using it in single-family houses. The electric and thermal power of the system is 2.5 kWe and 25 kWt, respectively. A working prototype of the system was built in 2014 and since then it has been the subject of different kinds of studies. The results of the preliminary research show that the prototype of the ORC system functions properly and achieves its predicted performance. This research was carried out in laboratory conditions that usually differ from real operating conditions. The article presents the results of further testing intended to verify whether the prototype operates properly under various operating conditions. During the tests, the system's performance was evaluated based on the changes in such parameters as thermal load, flow rates of the working mediums and electrical load of the turbo generator. In the course of the research, the following parameters were measured: temperatures, pressures, flow rates and electrical parameters associated with the operation of the turbo generator. The obtained results demonstrate that the prototype of the ORC system was able to operate correctly despite abrupt changes in some of these parameters. Furthermore, the safeguards applied to the regulation system protected the safety of people in the vicinity of the installation as well as the installation itself against damage. Lab tests have also shown that the oil-free turbogenerator-equipped with gas bearings-can operate over a wide range of rotational speeds, allowing adjustment of the generated power according to the current energy demand.