• Energy Research
• US close
• BD close
• Southeast University close

Abstract A three-dimensional two-fluid model is established for an in-situ gasification chemical looping combustion system to predict its dynamic characteristics and non-uniformity in gas-solid distribution. In the experiment, the fuel reactor (FR) and air reactor (AR) were designed as a high-velocity riser and a novel low-velocity moving bed, respectively. Simulations results show that the predicted pressure distributions agree reasonably well with the experimental data. AR operation did not show any obvious influence on oscillations in the full-loop particle circulation. Each stage of the moving bed AR is found to operate better at relatively lower gas fluidizing number, and the maximum allowable fluidizing number is estimated to be around 0.7. With increase in fluidizing number in AR, gas concentration, gas velocity and solid velocity uniformity index increase, while solid concentration uniformity index decreases. Compared to the parallel arrangement of gas distributors and exhausts, gas concentration and velocity uniformity indices are smaller except for the near-exhaust section under the vertical arrangement of gas distributors and exhausts. Increase in first-stage or second-stage AR outlet pressure has an opposite influence on gas leakage in both the first-stage AR and second-stage AR.

In order to solve the problem of wind curtailment, the heat storage electric boiler is used to promote clean heating in the heating season in northern China. When the room temperature of the heating room changes in a certain range, it will not cause user discomfort, so there is a certain adjustment space for the electric heating equipment. Through aggregator, it can benefit both sides by aggregating several heat storage electric boilers to participate in demand response. In this paper, based on the chance constrained programming, considering the influence of uncertain factors such as weather and user randomness, day-ahead and intraday optimization models for demand response of the thermostatically controlled loads aggregator are established. The objective function of the day-ahead optimization is to maximize the benefits of aggregators, and the objective function of the intraday optimization is to smooth the fluctuation of renewable energy. Finally, the feasibility of the model is verified by an example.

AbstractIt is necessary to disclose the two-phase interphase behavior in the liquid desiccant dehumidifier/regenerator applicable for air conditioning, but the present investigation is far from enough. In this paper, the surface structure of liquid desiccant solution is analyzed by molecular dynamics simulations. LiBr-H2O is chosen as the working solution with a concentration of 1 M and the system model is built with Gromacs. System temperatures vary from 300 to 350 K covering the temperature range of liquid desiccant dehumidification and regeneration. Density profiles of ions and water molecules are plotted along the vertical directions, and their distribution preferences on the solution surface are discussed. With the molecular simulation, it is found there is an ions-vapor layer with a thickness of 6–9 Å between the saturated vapor and bulk solution, which is not shown in the traditional macroscopic models. The results show that the density of water remains stable in the bulk while decreases sharply on the solution surface. However, the salt ions, i.e. Li+ and Br-, have a peak density on the surface. This ions-vapor layer behaves like a buffer to transfer water molecules from/to the bulk solution. More research will be required to investigate how to control the ions-vapor layer, so that air dehumidification and solution regeneration can be easily operated, which provides significant energy savings for the liquid desiccant air conditioning.

With the impacts of climate disruption becoming more evident there has been an increase in the uptake of climate change adaptation "toolkits" to assist local governments build community resilience and adapt to the impacts of climate change. There is increasing attention and call for practitioners to adopt proactive and participatory approaches to help in the adaptive response planning process. One such toolkit is the International Council for Local Environmental Initiatives (ICLEI) Asian Cities Climate Change Resilience Network (ACCRN) Process (IAP). This is a simple but rigorous toolkit developed to help local governments in Asian cities build resilience to the impacts of climate change. This paper outlines the application of the toolkit to determine its versatility in the rural context and was trialled in the Himalayan rural enclave of Ramgad in the Indian state of Uttarakhand. Given the differences between urban and rural environments, the outcomes highlighted the need for further investigation and analysis into the process to ensure that the methodology truly reflects the nature of rural systems and their level of vulnerability and adaptive capacity. Overall, the toolkit proved to be a simple but versatile toolkit to assess the vulnerability and adaptive capacity of communities in rural Himalaya. Over 40 resilience intervention strategies were developed for the Ramgad enclave and these were prioritized according to their technical, political, social and economic feasibility.

The global issue of climate change has accelerated the international commitment to net-zero carbon emission development. Decarbonizing the building sector has been put on several governments’ sustainable development agendas. To provide a reference for decarbonizing the building sector, this paper summarizes the U.S. experience in zero-carbon buildings (ZCBs) from the aspects of policies, codes, and standards at the federal and local levels and those of professional societies. Based on the definition and boundaries of ZCBs, this paper introduces policies on building energy efficiency, electrification, on-site renewable energy deployment, and “buy clean”, illustrating highlights in building phases, energy systems, materials production, and fiscal incentives. The synergic efforts and coordination between federal and local levels and with professional societies are also introduced. Successful experiences in policy and standard implementation are summarized, including the systemic work of multilevel governance, clearly defined goals and stringent policies, constant upgrades of codes and standards, transparency in reporting and information sharing, and increased financial and investment opportunities. This paper provides concrete recommendations for developing zero-carbon building policies.

Online monitoring is the precondition to achieve state maintenance and lifecycle management in power grid. Also, effective data transform model is the basis of online monitoring. We propose a data transform model for intelligent substation and PMS device online monitoring based on analyzing Standards of intelligent substation and State Grid. The PMS data are classified and compared with data model of IEC 61850 Standard. With methods of tag mapping and ID index we achieve the data conversion between intelligent substation and PMS.

This paper presents a microgrid system model considering three types of load and the user’s satisfaction function. The objective function with mixed zero-one programming is used to maximize every user’s profit and satisfaction in the way of the demand response management under real-time price. An energy function is used to transform the constrained problem into an unconstrained problem, and two neural networks are used to find the local optimal solutions of the objective function with different rates of convergence. A neurodynamic approach is used to combine the neural networks with the particle swarm optimization to find the global optimal solution of the objective function. The simulation results show that the combined approach is effective in solving the optimal problem.