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Liquid-desiccant dehumidification system in building air-conditioning has high energy efficiency in comparison to traditional dehumidification technology that needs to cool air below the dew point temperature. Since the dehumidification process dominates the performance of a liquid-desiccant system, this study aims to develop a deeper understanding in the dehumidification performance of some liquid desiccants. Then, an experiment test was conducted to determine the CaCl2-LiCl mixed liquid-desiccant system in a dehumidification system. The effects of the pure and mixture liquid desiccant solution on the moisture removal rate, refrigerating capacity and dehumidification performance were compared and analysed. Results show that with the increase in the LiCl concentration, the dehumidification capacity and dehumidification coefficient first increased rapidly and then increased slowly after 30% LiCl concentration. According to the economic analysis of mixed salt solution, the mixed LiCl and CaCl2 solution with a mixing ratio of 3:1 would achieve the best optimal dehumidification efficiency and would incur a low system cost under the working conditions of a dry-bulb temperature at 26°C and a relative humidity of 60% of fresh and return air.

A building may be subjected to a variety of accidental loads during its service life. Partially precast concrete (PC) beams are a primary structural component. Their impact resistance can have a substantial impact on the overall safety of a structure when it is subjected to an impact load. In this study, numerical analyses were performed on the dynamic response of PC beams strengthened with bonded steel plates subjected to impact loading. The model was verified from four aspects: energy conversion, failure form, impact force–time history curve, and midspan displacement–time history curve. The dynamic response eigenvalues of the peak impact force, peak midspan displacement, and residual midspan displacement were compared between the numerical simulations and experimental tests. The relative inaccuracy of the peak impact force ranged from 9.51% to 14.0%, with an average value of 11.9%. The average relative error for the midspan displacement was −0.09%, with the greatest relative errors varying between −0.64% and 0.3%. The residual value errors of the midspan displacement ranged from −0.95% to 2.38%, with an average relative error of 0.94%. On this basis, the effects of the impact mass, impact height, width, and length of the bonded steel plate on the impact resistance of the components were evaluated. Furthermore, the differences in the equivalent plastic strain contours, impact force–time history curves, and midspan displacement–time history curves under different parameters were compared. The results demonstrated that the failure modes and flexural deformations of the test beams were influenced by the impact mass and impact height. The increase in the length and width of the steel plate had no effect on the impact force response, but the peak and residual values of the midspan displacement decreased, which could significantly increase the impact resistance of the beams. Lastly, the impact mass m, the impact height h, the thickness t of the bonded steel plate, the length of the bonded steel plate hs, and the width of the bonded steel plate bs were all taken into account in the fitting formula. These five parameters were used to predict the peak impact force response, the peak value of the midspan displacement, and the residual value of the midspan displacement. The results demonstrated that the fitting formula had small errors and could accurately reflect the dynamic responses of the PC beams strengthened with bonded steel plates under impact loading.

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