The research project TRI-MAX has as main objective the development, construction and experimental assessment in real environment of a thermal engine based on Trilateral Flash Cycle (TFC), which recovers waste heat and converts it into power. The TFC is consisted by the same components with an Organic Rankine Cycle, with the only difference that the organic working fluid is heated up to the saturation temperature under high pressure rather than vaporized. As the organic fluid expands from the saturation, instantaneously changes phase (flashing process), resulting in a significant reduction of the irreversibilities generation through the avoided intermediate processes.

The cycle design will take place for low temperatures (up to 130oC), while the cycle thermal power is estimated around 10-15 kW. The project goal is the efficiency increase of the thermal energy conversion to electricity, up to 20% in comparison with the traditional ORC technologies, which are mainly in use today and present low efficiency (5-6%) for waste heat recovery from low-temperature heat sources. This goal will be achieved taking advantage of two significant characteristics of the TFC, in order to maximize the cycle efficiency according to the 1st and 2nd Thermodynamic Laws. These two characteristics are:

•      Prevention of the isothermal vaporization.

•      Adjustment of the pinch-point during the fluid heating.

The specific objectives to be achieved for the project successful completion, are:

•      Study and analysis of the two-phase flow during expansion, in order to evaluate how it affects the whole cycle.

•      Analysis of the power cycle processes in order to optimize its efficiency.

•      Development of the simulation and optimization tool for the expansion process and the entire cycle.

•      Detailed design of the TFC for 10-15 kW and test runs.

•      Experimental tests for the cycle operation in laboratory.

•      TFC tests in real field.

•      Technoeconomical assessment of TFC and comparative analysis with competitive technologies.



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