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The integrated system of AWKRC (ammonia–water Kalina–Rankine cycle) is a novel cycle operated on KC (Kalina cycle) for power generation in non-heating seasons and on AWRC (ammonia–water Rankine cycle) for cogeneration of power and heating water in winter. The influences of inlet temperatures of both heat resource and cooling water on system efficiencies were analyzed based on the first law and the second law of thermodynamics. The calculation is based on following conditions that the heat resource temperature keeps 300 °C, the cooling water temperature for the KC or AWRC is respectively 25 °C or 15 °C; and the temperatures of heating water and backwater are respectively 90 °C and 40 °C. The results show that the evaluation indexes of the power recovery efficiency and the exergy efficiency of KC were respectively 18.2% and 41.9%, while the composite power recovery efficiency and the composite exergy efficiency of AWRC are respectively 21.1% and 43.0% accounting both power and equivalent power of cogenerated heating capacity, including 54.5% heating recovery ratio or 12.4% heating water exergy efficiency. The inventory flow diagrams of both energy and exergy gains and losses of the components operating on KC or AWRC are also demonstrated. [ABSTRACT FROM AUTHOR]

A modified dual-pressure vaporization Kalina cycle (DPV–KC2) is proposed with the second evaporator installed parallel to the economizer and both are in series after the first evaporator. The merit is to acquire higher efficiency by reduced thermal irreversibility in heat transfer between heat source and working medium. The parameter optimizations were conducted with power recovery efficiency as the cycle performance evaluation index. The calculation conditions are set as that the inlet temperatures of heat source and cooling water are 400 °C and 25 °C respectively with the constraints such as heat transfer pinch point temperature differences are proper, the maximum evaporation pressure does not exceed 20 MPa, the vapor quality at the turbine outlet is greater than 0.85 and the exhaust temperature of heat source is not lower than 90 °C. The optimal parameters obtained include concentrations of work solution and basic solution of 0.5 and 0.3138 respectively, the evaporation dew point temperature of 300 °C, the supercool at outlet of economizer of 5 K and the superheating at the second evaporator outlet of 75 K respectively. And the corresponding power recovery efficiency of the DPV–KC2 reaches 26.4%, which is 3.4% and 15.2% respectively higher than that of the DPV–KC and the Kalina cycle. [ABSTRACT FROM AUTHOR]