摘要 |
A method of low temperature energy storage and utilization is disclosed which can be used in conjunction with low temperature heat sources such as solar energy flat plate collectors. Input heat energy is utilized to sustain the endothermic dissociation of ammonium carbamate produced from a reaction between urea and water. The energy is retained in the form of the higher energy containing dissociation products ammonia and carbon dioxide. The dissociation products are separated by liquifying and draining off the ammonia and are held under pressure. The stored heat is extracted in the form of output heat energy for an end use by reversing the dissociation reaction and combining the ammonia and carbon dioxide to form ammonium carbamate which becomes urea and water and is recirculated as a slurry. Closed-loop, fluid-medium heat exchange systems can be used both in the input and output sides of the energy system. The entire system operates at temperatures of less than 250 DEG C. If desired, the system may be operated more efficiently and the corrosive properties of the urea-water slurry reduced by minimizing the formation of urea.
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