A study on Kalina solar system with an auxiliary superheater

Based on the Kalina cycle, the solar-boosted system with an auxiliary superheater is investigated in the current paper. To predict the system performance, the corresponding calculation model is built. In accordance with engineering practice, the maximum pressure of the system is within 3 MW and the pinch point temperature difference of the regenerator is not less than 0.5 °C in this paper. Then based on the characteristics of the Kalina solar system, the verification items are given to verify the correctness of the calculation model. Afterward the model is proven to be correct by sampling check a set of calculation data. Further, parameter performance analyses are carried out on the system. Results show that the system pressure difference is an important performance benchmark that can be used to evaluate the thermal efficiency of the power generation cycle. Furthermore, the relationship between the optimal mass flow rate and total heat transfer rate is noticeable in the solar system since solar radiation is changed with time. And the corresponding approximate expression is thus derived for optimal operation. Finally, an application case is designed by using direct normal solar radiation data in Tosashimizu city of Japan based on average hourly statistics.

► System pressure difference is an important performance benchmark.
► The real-time optimal control of the solar system is given for higher performance.
► From system scale, economy and safety viewpoints, the superheater is important.
► Fitting method is introduced for qualitative investigation.