With the continuous growth of the population and the improvement of production, the shortage of freshwater has plagued many countries. The use of novel technologies such as desalination to produce fresh water on a large scale has become inevitable in the world. Hydrate-based desalination (HBD) technology has drawn an increasing amount of attention due to its mild operation condition and environmental friendliness. In this paper, literature on hydrate-based desalination is comprehensively analyzed and critically evaluated, focuses on experimental progress in different hydrate formers that have an impact on thermodynamics and dynamics in hydrate formation. Besides, various porous media promotion is investigated. Besides, the hydrate formation morphology and hydrate crystal structure with different hydrate formers are analyzed and compared. Moreover, molecular dynamic simulation is discussed to further understand microscopic information of hydrate formation. Furthermore, simulations of the HBD process by considering the energy consumption are also investigated. In conclusion, the hydrated based desalination is a potential technology to get fresh water in a sustainable way.

Jibao ZHANG ,   Shujun CHEN   et al.
Passive residual heat removal heat exchanger (PRHR HX), which is a newly designed equipment in the advanced reactors of AP1000 and CAP1400, plays an important role in critical accidental conditions. The primary and secondary side coupling heat transfer characteristics of the passive residual heat removal system (PRHRS) determine the capacity to remove core decay heat during the accidents. Therefore, it is necessary to investigate the heat transfer characteristics and develop applicable heat transfer formulas for optimized design. In the present paper, an overall scaled-down natural circulation loop of PRHRS in AP1000, which comprises a scaled-down in-containment refueling water storage tank (IRWST) and PRHR HX models and a simulator of the reactor core, is built to simulate the natural circulation process in residual heat removal accidents. A series of experiments are conducted to study thermal-hydraulic behaviors in both sides of the miniaturized PRHR HX which is simulated by 12 symmetric arranged C-shape tubes. For the local PRHR HX heat transfer performance, traditional natural convection correlations for both the horizontal and vertical bundles are compared with the experimental data to validate their applicability for the specific heat transfer condition. Moreover, the revised natural convection heat transfer correlations based on the present experimental data are developed for PRHR HX vertical and lower horizontal bundles. This paper provides essential references for the PRHRS operation and further optimized design.

Zhimin QIU ,   Daogang LU   et al.
The development of the climate-change-mitigation technology has received widespread attention from both academic and policy studies. Nevertheless, very few studies have explained how and why economies contribute differently to global development. This paper decomposed the development of the global climate-change-mitigation technology, proxied by patent-based indicators, from 1996 to 2015 into several predefined factors. The results show that the worldwide surge of climate-change-mitigation-technology patents from 1996 to 2011 is driven by increased concentration on green invention, improved research intensity, and enlarged economic scale, while the falling of patent counts from 2011 to 2015 is predominantly due to less concentration on green invention. Among different climate-change-mitigation technologies, the type-specific development is attributed to different dominant factors, and the resulting priority change can reflect the shift of both global research and development (R&D) resource and market demand. Regarding regional contributions, the resulting economy-specific contributions to each driving factor can be used to design the policies to promote the development of the global climate-change-mitigation technology.

Liying SONG ,   Jun JING   et al.
Solar energy is one of the most promising forms of renewable energy for solving the energy crisis and environmental problems. Dust deposition on photovoltaic mirrors has a serious negative impact on the photoelectric conversion efficiency of solar power stations. In this paper, the influence mechanism of the dynamic and static liquid bridge forces on particle deposition behaviors on solar photovoltaic mirrors is investigated. In addition, the expression and physical meaning of the particle critical separation velocity are proposed. The research results show that the static liquid bridge force can be the primary deposition force causing dust particles to adhere to photovoltaic mirrors. However, the dynamic liquid bridge force can act as a resistance force for the particle motion process and even make dust particles roll along and finally stay on the mirror. The contact force is the primary separation force that causes dust particles to flow away from the mirror. Whether dust particles adhere to the mirror depends on the relative size of the deposition and separating forces. The particle critical separation velocity describes the relative size of the collision-rebound effect and mirror adhesion effect and is expressed in Eq. (16). These research findings can provide theoretical guidance for mirror cleaning methods in the operation process of photovoltaic mirrors.

Xueqing LIU ,   Xiaodong ZHAO   et al.

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