## 4 Conclusions  
This research describes a detailed study undertaken to investigate the energy and exergy performance of a combined IRCC corn dryer. The key findings according to the results of the research can be summarized as below:  
1. The average drying rate of corn drying system in the current dryer was 1.1 gwater/gwet matter h. According to the drying rate, the drying process of corn can be divided into three stages; he dehydration of each stage accounts for 25.66%, 44.38% and 29.96% of total, respectively;
2. The energy efficiency of the entire drying system ranged from 2.16% to 35.21%. Additionally, the SEC of the whole drying system increases rapidly (19,844.52-42,425.59 kJ/kg) due to the effect of the binding energy after 540 min, indicating that energy efficiency ought to be optimized in this period;
3. The overall recovered radiant energy and the average radiant exergy rate were 674,339.3 kJ and 3.54 kW, respectively. Moreover, the wavelength range of the radiator with slight fluctuation (between 7.68 \(\upmu\)m and 8.3 \(\upmu\)m) indicated that the corn quality has been improved correspondingly under the suitable far-infrared radiation absorption rate;
4. Heat loss in the outlet air, the corn kernels and to the chamber wall were found to be 20,045.23 MJ, 12,547.16 MJ and 5151.52 MJ, accounting for 53.11%, 33.24% and 13.65% of the total, respectively. It is of great significance to design a waste-heat recovery device in view of reducing exhaust heat-loss and energy-consumption costs--especially in the later stages of the drying process.  
Figure 13: Variations of \(\eta_{\text{ex}}\) and SI with the drying process of (**a**) the whole drying system and (**b**) the DC.  
The average exergy rate for dehydration was 462 kW; the exergy efficiency of the whole drying system varied from 5.16% to 38.21%, indicating that the IRCC corn dryer had a productive exergy performance;
6 Measures should primarily be put in place to optimize the CC, below by the DC, HE and RA according to the contribution level to the total exergy destruction.  
The present work revealed the performance evaluation of the IRCC corn dryer regarding energy consumption. The main conclusions of the present work may help to better understand the energy system of the drying system and scientifically guiding the design of the drying equipment. Further research is recommended to develop the optimum controller of industrial grain drying system based on the theoretical basis provided by the present work to obtain the higher quality corn at acceptable energy consumption.  
Methodology, C.L. ([PERSON]) and B.L.; software, C.L. ([PERSON]) and J.H.; writing--original draft preparation, C.L. ([PERSON]); supervision, project administration, C.L. ([PERSON]); data curation, C.L. ([PERSON]), B.L. and J.H. The final version of the manuscript was reviewed and agreed by all authors. All authors have read and agreed to the published version of the manuscript.  
This project was funded by the National Natural Science Foundation of China (no. 31671783; no. 31371871) and Science and Technology Planning Project of Guangdong Province, China (no. 20148020207001).  
The authors would like to thank to the editors and reviewers for their valuable and constructive comments.