Xiaofeng Zheng

Bio: Xiaofeng Zheng is an academic researcher from University of Nottingham. The author has contributed to research in topics: Blower door & Building airtightness. The author has an hindex of 10, co-authored 25 publications receiving 655 citations.

A review of thermoelectrics research – Recent developments and potentials for sustainable and renewable energy applications

Abstract: In recent years, thermoelectric (TE) devices have emerged as promising alternative environmental friendly applications for heat pumps and power generators since the environmental issues such as the global warming and the limitations of energy resources gradually drew worldwide attentions. Due to the green feature and distinct advantages, the thermoelectric technology have been applied to different areas in an effort of designing simple, compact and environmental friendly systems. The applied areas are extended from the earliest application on kerosene lamp to aerospace applications, transportation tools, industrial utilities, medical services, electronic devices and temperature detecting and measuring facilities. The application potentials of TE in directly conversing thermal energy into electrical power have been identified, especially for where the cost of thermal energy input need not to be considered, such as waste heat utilization, in the light of the present low efficiency of thermoelectric conversion. The capability of TE in producing thermal energy (in terms of cooling or heating) with the use of electrical power is also well identified. This paper reviews the status of the material development and thermoelectric applications in different areas and discusses the difficulties in terms of the commercialisations of advanced materials. Other than this, the main purpose of this paper is to present the great potential of achieving both environmental and economic benefits by exclusively utilizing thermoelectric applications in different areas. It also comes to the conclusion that the thermoelectric applications with the current conversion efficiency are economically and technically practical for micro/small applications. However, it would be transformed to a more significant green energy solution for improving the current environment and energy issues by using medium/large scale thermoelectric applications when the thermoelectric materials with a figure-of-merit over 2 come into commercial practice.

Recent progress in liquid desiccant dehumidification and air-conditioning: A review

Abstract: This paper presents a literature review on the recent research progress in liquid desiccant dehumidification and air conditioning systems. The physical features of various liquid desiccant materials and their dehumidification performances have been summarized. With the aim to improve the dehumidification characteristics, mixed solvents desiccants have become research hot topics recently. Various types of dehumidifiers and their integration with liquid desiccant dehumidification system have been reviewed. The combination of liquid desiccant dehumidification system with solar collector, vapour compression system, heat pump system, CHP system, etc. have been grouped and compared. It is shown that the majority of the recent research work for liquid desiccant dehumidification systems has concentrated on numerical simulations, a considerable amount of works are still required for the practical investigations of innovative material (mixed solvents) and hybrid systems.

An experimental study of a novel prototype for two-stage thermoelectric generator from vehicle exhaust

Abstract: For the vehicle engine, about 30% of the primary energy is discharged as waste heat in the exhaust gases. The recovering of heat from that is a noticeable promising application of thermoelectric power generation (TEG). In this paper, a novel prototype for two-stage TEG from vehicle exhaust has been proposed. After system modeling, an experiment structure has also been built and tested for further study. Results of both theoretic analysis and experiment show the reasonability for exhaust heat recovery. The prototype can generate a maximum power output of about 250 W when operating at hot side temperature 473 K. The system thermal efficiency can reach 5.35%, it is improved by 32% compared to 4.04% of single stage TEG in the same operating conditions. System optimization and future improvement of the prototype is also discussed. Finally, based on a vehicle made by our research funder, economic value for commercialization in diesel vehicles has been analyzed.

American Society for Testing and Materials

Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

High Performance Thermoelectric Materials: Progress and Their Applications

Abstract: Thermoelectric (TE) materials have the capability of converting heat into electricity, which can improve fuel efficiency, as well as providing robust alternative energy supply in multiple applications by collecting wasted heat, and therefore, assisting in finding new energy solutions. In order to construct high performance TE devices, superior TE materials have to be targeted via various strategies. The development of high performance TE devices can broaden the market of TE application and eventually boost the enthusiasm of TE material research. This review focuses on major novel strategies to achieve high-performance TE materials and their applications. Manipulating the carrier concentration and band structures of materials are effective in optimizing the electrical transport properties, while nanostructure engineering and defect engineering can greatly reduce the thermal conductivity approaching the amorphous limit. Currently, TE devices are utilized to generate power in remote missions, solar-thermal systems, implantable or/wearable devices, the automotive industry, and many other fields; they are also serving as temperature sensors and controllers or even gas sensors. The future tendency is to synergistically optimize and integrate all the effective factors to further improve the TE performance, so that highly efficient TE materials and devices can be more beneficial to daily lives.