Ispitivanje demonstracijskog postrojenja plinske turbine zatvorenog ciklusa s nadkritičnim CO2 kao radnim medijem

The development of a closed cycle gas turbine with super-critical carbon dioxide as a working fluid is under way in order to generate power from waste heat source of a low or intermediate temperature range from industry. Its demonstration test plan using a reduced scale turbomachine is described. Principal specifications follow; net power output of around 10 kWe and recirculation CO2 flow rate of 1.2 kg/s. Optimized range of compressor inlet temperatures as well as pressure is investigated under the given turbine inlet conditions of 550 K and 12 MPa respectively. Given these inlet conditions, a suitable type of turbomachine is selected to be radial. Based on the conventional design method assuming ideal gas an optimal dimension of the outer wheel diameter is predicted to be 20mm for compressor and 30mm for turbine under an optimal rotational speed of 100,000 min-1.U tijeku je razvoj plinske turbine zatvorenog ciklusa s nadkritičnim ugljikovim dioksidom kao radnim medijem za proizvodnju električne energije iz nisko ili srednje temperaturne otpadne topline iz industrije. Opisano je ispitivanje demonstracijskog postrojenja s turbinom u umanjenom mjerilu. Glavne karakteristike su: neto izlazna snaga od približno 10 kWe i protokom CO2 od 1.2 kg/s. Istraživano je optimalno područje ulaznih temperatura i tlakova kompresora za zadane ulazne parametre turbine od 550 K i 12 MPa. Za zadane ulazne uvjete, odabran je kao odgovarajući radijalni tip turbostroja. Na temelju uobičajenih metoda konstruiranja i pretpostavljajući idealni plin određene su optimalne vrijednosti vanjskih promjera rotora kompresora 20 mm i rotora turbine 30 mm uz optimalnu brzinu vrtnje od 100.000 min-1

THERMAL-HYDRAULIC CHARACTERISTICS OF MICROCHANNEL HEAT EXCHANGER AND ITS APPLICATION TO SOLAR GAS TURBINES

ABSTRACT Incorporating "integral method" proposed here, a set of empirical correlations of local heat transfer coefficient and pressure loss coefficient are newly derived based on experiments using microchannel heat exchanger (MCHE) with supercritical carbon dioxide as heating medium and water as coolant. They are expressed in dimensionless forms of polynomial of Reynolds number and Prandtl number. The same correlation of Nusselt number is found applicable to both fluids and its value is almost two times larger than Dittus Boelter correlation. It was also shown that the above form is applicable to a wide range of geometry with the values of constants changed. Accuracy of both correlations is confirmed within 5% errors for MCHE with S-shaped fins in the range of pressures 9~12.5MPa and temperatures 280~390K. Based on the correlations, sizes of heat exchangers are evaluated contained in gas turbine cycle with super critical carbon dioxide as a working fluid applicable to solar power