The Performance of the Kalina Cycle System 11(KCS-11) With Low-Temperature Heat Sources

Abstract

The possibility of exploiting low-temperature heat sources has been of great significance with ever increasing energy demand. Optimum and cost-effective design of the power cycles provide a means of utilization of low-temperature heat sources which might otherwise be discarded. In this analysis, the performance of the Kalina cycle system 11 (KCS11) is examined for low-temperature geothermal heat sources and is compared with an organic Rankine cycle. The effect of the ammonia fraction and turbine inlet pressure on the cycle performance is investigated in detail. Results show that for a given turbine inlet pressure, an optimum ammonia fraction can be found that yields the maximum cycle efficiency. Further, the maximum cycle efficiency does not necessarily yield the optimum operating conditions for the system. In addition, it is important to consider the utilization of the various circulating media (i.e., working fluid, cooling water, and heat resource) and heat exchanger area per unit power produced. For given conditions, an optimum range of operating pressure and ammonia fraction can be identified that result in optimum cycle performance. In general, the KCS11 has better overall performance at moderate pressures than that of the organic Rankine cycle.

Energy and exergy analysis of integrated system of ammonia–water Kalina–Rankine cycle

“…Bombarda et al [14] conducted a comparison between the thermodynamic performances of Kalina cycle and an ORC cycle, for the case of heat recovery from two diesel engines, and the calculation results show that the quantities of net electric power produced by the Kalina cycle and the ORC are about the same. Hettiarachchi et al [16] investigated the performance of the Kalina cycle system with low temperature heat sources and found that the dual pressure KC has better overall performance at moderate pressures than that of the ORC.…”

An Assessment of Global Ocean Thermal Energy Conversion Resources With a High-Resolution Ocean General Circulation Model

“…(1) (gross power density) taken at standard conditions DT ¼ 20 C and T ¼ 300 K. The average seawater density q is taken as 1025 kg m À3 , the seawater specific enthalpy c p as 4000 J kg À1 K À1 , and the OTEC combined turbo-generator efficiency e tg as 0.75. Despite their simplicity, the proposed power formulas capture the basic behavior of OTEC systems based on pure-fluid, low temperature Rankine cycles, with thermodynamic efficiencies approximately half the Carnot limit of DT over T. If more complex cycles were considered, e.g., of the Kalina type [22], Eqs. (1) and (2) should be modified accordingly.…”

Heat recovery from Diesel engines: A thermodynamic comparison between Kalina and ORC cycles

“…At present, the heat recovery from high temperature gases, as in the modern combined cycles, or in multi-megawatts coal thermoelectric plants, is monopolized by the steam Rankine cycles and the more believable application of the Kalina cycle is restricted to medium-low temperatures heat sources (typical maximum temperatures of 300-400 • C in the case of heat recovery, and 100-120 • C in the binary geothermal plants) and to small power conversion systems [8,9,10,11].…”