Xiaoliang Tian’s research while affiliated with Qingdao University and other places

A novel concentration difference energy accumulator was evaluated. This accumulator was framed by hollow fiber membranes as the water vapor transfer channels. This was the membrane energy accumulator (MEA). A mathematical model was created to simulate the heat and mass transfer in the crystal dissolving process of the energy discharging stage. In addition, the model was experimentally validated. Based on the simulation results, the heat and mass transfer characteristics of the MEA in the crystal dissolving process were analyzed. The results of the simulation and experiments proved the feasibility of the MEA. The energy storage capacity of the MEA was a minimum of 25% greater than that of a traditional concentration difference energy accumulator. The effectiveness of the MEA was confirmed.

Biogas production from organic wastes has been widely utilized for several decades, but maintaining right temperature for anaerobic bacteria is a challenge. In order to overcome the inhibition of the bacteria growth and biogas production due to the low temperature, a solar-biogas hybrid energy system for heating, fuel supply, and power generation has been proposed for converting domestic garbage into biogas in a rural area of China. In this system, the solar energy has been included as one of the heating sources during an anaerobic digestion process. A mathematical model has been developed to evaluate the influence of system operating characteristics. Based on the simulation results, the biogas production rate, thermal efficiency, temperature of the digester, energy distributions in the system, optimal operating parameters, economic efficiency, and thermodynamic characteristics of the system were analyzed. The impact of solar irradiation on the efficiency of the system was also studied. According to the results, in cloudy days, the reactor volume and solar collector area greatly influenced the steady energy supply. In winter, the produced biogas is mostly utilized by the aided boiler to maintain the proper organic mixture temperature in the bioreactor. Heat loss from bioreactor dramatically increases the organic mixture volume. Per simulation, the longest return on the investment of this type of the biogas system is about 5.54 years, and the shortest return on the investment is less than 4 years if the battery is removed and the electric grid can be used. Therefore, in this study, the feasibility of a hybrid energy system for converting domestic garbage into energy has been validated. Copyright

The pump-assisted separate heat pipe (PASHP) has a broad application prospect in the field of saving energy. Two-phase flow boiling in PASHP is a multifarious physical process and the study of the characteristic of the flow boiling in PASHP is significant. The experimental investigation of two-phase flow boiling of R134a in PASHP was conducted. The results indicate that the flow patterns agree with the Wojtan-Ursenbacher-Thome map. The pressure drop has been compared with Muller-Steinhagen-Heck correlation, and the compared results indicate that the experimental data are inside the 10% confidence interval predictions. The heat transfer coefficients were compared with correlation given by Mohseni. It indicates that all the experimental data are inside the 10% confidence interval predictions at x>0.1. However, part of error is beyond 30% at x≤0.1. A new heat transfer coefficient correlation was developed, and most of the estimated values are within an error band of ±10% of the experimental data.

The silica gel–water adsorption refrigeration has attracted much attention especially in the last two decades, due to its environmentally friendly refrigeration that can be powered by low grade heat source. In this paper, we reviewed the research about silica gel–water adsorption technology, cooling systems as well as heat pumps. The technological developments of silica gel–water adsorption refrigeration, including working pairs, heat and mass transfer, cycle and system design, simulation work, prototypes and applications, were discussed. The advantages of silica gel–water adsorption refrigeration technology as well as its disadvantages were elucidated. Finally, the prospect of this refrigeration method was analyzed. The weak heat and mass transfer performance of the adsorbent material was the main bottleneck of the silica gel–water adsorption refrigeration technology and resulting in large size, low performance and high cost.