Experimental and Computational Heat Losses for a Small Dish Receiver

Experimental and computed losses and reactor tube temperature profiles are presented for three ammonia receiver/reactor geometries operating on a 9 m dish concentrator. Preliminary analysis of receiver losses indicates that as the half cone angle of the receiver tube frustum reduces – from 17.5o to 7.5o to 3.7o – there is a shift from convection-dominated losses to radiation-dominated losses. The convection-dominated losses decrease because the receiver becomes more inverted towards solar altitudes of 90o, while the radiationdominated losses increase because the reactor tube temperature increases.