Solar driven ammonia-absorption cooling machine

In an air cooled absorption cycle cooling machine adapted to use an aqueous solution of ammonia as the thermodynamic work fluid and having a generator device for separating ammonia vapor from the solution, the improvement in such generator so as to be capable of use with a solar heater or other source of heat of a relatively low temperature capable of heating water to temperatures between 120.degree. C. and 150.degree. C. and of delivering an energy rate above 7000 Watts per ton of refrigeration;

• comprising a generator core in the form of an elongated tank through which the circulation of ammonia solution is subject to separation of ammonia from solvent water when the solution temperature is raised through heat exchange relationship across a wall of said core with a circulating stream of hot water, a generator jacket coaxially disposed surrounding said core and defining an annular hot water axial-flow circulation chamber;
• a multitude of closely spaced substantially axially-aligned heat transfer fins having an axial length on the order of 50 mm or less and being mounted on the wall of said generator core, said fins protruding into and substantially filling said annular chamber, any given pair of circumferentially adjacent fins being oriented face-to-face with any such upstream pair being axially obstructed immediately downstream by another similarly-oriented fin being offset in a staggered relation to said pair.