DUAL-TEMPERATURE THERMAL STORAGE USING AMMONIATED COMPLEX COMPOUNDS

CHILL AND HEAT STORAGE IS USEFUL IN SHIFTING ELECTRICAL LOAD FROM PERIODS OF PEAK POWER TO OFF-PEAK PERIODS. CHILL STORAGE SYSTEMS USING COMPLEX COMPOUNDS HAVE HIGHER STORAGE DENSITIES (BOTH MASS DENSITY AND VOLUMETRICALLY) THAN CONVENTIONAL SYSTEMS SUCH AS ICE STORAGE, AND CAN BE USED AT LOWER TEMPERATURES. THE COMPOUNDS ADSORB AMMONIA DURING DISCHARGE OF THE CHILL STORAGE AND CAN BE DIRECTLY COUPLED WITH AMMONIA REFRIGERATION SYSTEMS. THEY ARE CHARGED BY DESORBING THE COMPLEX COMPOUNDS WITH A COMPRESSOR DURING OFF-PEAK HOURS. COMPLEX COMPOUNDS CAN ALSO BE USED AS STORAGE MEDIA FOR DUALTEMPERATURE TES, PROVIDING BOTH HEAT AND CHILL STORAGE WITHOUT ANY ADDITIONAL EQUIPMENT COMPARED TO THAT REQUIRED FOR CHILL STORAGE ALONE. THE DIFFERENCE IN TEMPERATURE BETWEEN THE TWO STORAGE TEMPERATURES IS DETERMINED BY THE VAPOR PRESSURE CURVE OF THE AMMONIATED COMPLEX COMPOUND. THE PURPOSE OF THIS PROJECT IS TO DEMONSTRATE DUAL TEMPERATURE CHILL STORAGE ON A LABORATORY SCALE AND USE LABORATORY RESULTS TO PROJECT SIZE AND COST OF A FULL SCALE SYSTEM. THE DEMONSTRATION WILL BE TIED TO AN ACTUAL DUAL TEMPERATURE TES APPLICATION AND WILL BE PERFORMED AT ACTUAL OPERATING TEMPERATURES AND PRESSURES. EVALUATION CRITERIA WILL BE (1) ABILITY TO PROVIDE HEAT AND CHILL STORAGE AT THE REQUIRED TEMPERATURES, (2) REFRIGERANT HOLDING CAPACITY, AND (3) APPROACH TEMPERATURE REQUIRED TO CHARGE (DESORB) THE SYSTEM;APPROACH TEMPERATURE HAVING A DIRECT INFLUENCE ON CHARGING ENERGY REQUIRMENTS.