Simulation analysis of performance optimization of gas-driven ammonia-water absorption heat pump

Abstract

Exchange (GAX) ammonia water absorption heat pump has a relatively high efficiency and the COP is improved by recovering internal heat. In order to resolve the problem that GAX effect becomes less obvious or even fails under the working condition of large temperature lift, a novel system is proposed to recover the rectification heat and absorption heat by solution split method. Compared with the method of using total strong solution to recover absorption heat after extracting rectification heat, the method of solution split avoids the problem of high temperature of inlet strong solution of the solution cooled absorber, and improves the internal heat recovery capacity of the system. When using solution split method to recover the rectification heat and absorption heat, the solution split ratio K has an important influence on the system performance. This paper will theoretically study the selection range of the solution split ratio K and the effect of evaporation temperature, cooling water temperature and generation temperature on the optimum split ratio K. Compared to the system that uses the total strong solution to recover the rectification heat and absorption heat, the performance of the novel system is significantly improved, and the novel system performance coefficient can be increased by up to 15.7%.

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