The vector analysis indicates that the heat recuperation depends not only on the values of heat transfer coefficient and temperature difference, but also on their coordination for the supercritical fluids. The splitting flow improves the coordination degree between temperature difference and heat transfer coefficient in low temperature recuperator, and increases the inlet temperature of heater and reduces the heat exhaust in the precooler, which leads to
the performance improvement of supercritical CO2 Brayton cycle. The present work is helpful to the system optimization and mechanism analysis of supercritical CO2 Brayton cycle.
With the decline of subsidy policy and implement of “double credit policy” in new energy vehicle industry, business model innovation will play an increasingly prominent role in the new energy vehicle industry. By analyzing the characteristics of policies, technologies and business models of China’s new energy vehicle market, and based on sociotechnical transformation theory, this paper constructs a business model evolution model under sociotechnical transformation. Then base on this model, there exist seven business model evolution paths from the perspective of sociotechnical transformation. For China’s new energy vehicle industry, five typical business model paths are studied in depth from four factors: landscape, regime, technology niche and business model. The research shows that the business model evolution model under sociotechnical transformation can clearly interpret the business model evolution path of China’s new energy vehicle industry. With the development of China’s new energy vehicle industry in the future, the impact of policy regime on business model innovation is weakening, and technology niche plays an increasingly important role in business model innovation.
The interest and possibilities of conducting steam gasification of biomass (SGB) assisted by concentrated solar energy (CSE) at high temperature as external heat source for applications at large scale is studied. First the different options to conduct SGB to produce syngas and hydrogen are analyzed. Thereafter the possibilities of integrating CSE in SGB are investigated, including the ways to transfer the heat to the reactor, as well as methods to increase fuel conversion efficiency and the solar share in the gas produced. Finally, some original ideas to conduct SGB with solid particles as energy carriers heated by CSE are proposed.
Future distribution systems will be penetrated with massive power electronics (PE) devices. This paper classifies the dynamics of future PE-rich distribution systems into four categories: dynamics introduced by network, dynamics introduced by PE interfaces, dynamics introduced by control of PE interfaces and dynamics introduced by load, generation and battery energy storage system. The purpose of such a categorization is to facilitate the analysis and control design of future distribution grids as well as to investigate the cause of instabilities. As a gridedge technology, a PE interface named Power Electronics Intelligence at the Network Edge (PINE) is used in numerical studies to demonstrate these four categories of dynamics and show how each of them influences the system dynamics and stability.
An evaluation of thermodynamic effects on leak detection and location estimation in natural gas pipelines was provided through non-isothermal process model. To estimate the process states (discretized pressures and mass flow rates) under varying thermodynamic conditions for leak detection and location estimation, a state and parameter estimation method (dual unscented Kalman filter) was proposed for the pipeline model. The dual unscented Kalman filter was adopted to estimate both the states and parameters in the presence of parameter uncertainties. Using the data generated from the nonisothermal model, the proposed new algorithm can detect the leak location efficiently and a real case study was performed to validate it.
Several approaches have been developed to illustrate shale gas supply chain network (SGSCN) in economically viable manner, but the connection between fracture geometry, gas production, and wastewater recovery has not received much attention. When fractures are created in unconventional reservoirs, the final fracture geometry significantly affects shale gas production rate and it indirectly determines the amount of recovered wastewater. To achieve a sophisticated understanding of this complex interaction, we focus on the development of a new framework to integrate dynamic modeling of hydraulic fracturing (HF), a reservoir simulator call CMG, and SGSCN. Based on this developed framework, we will determine the optimal configuration of SGSCN that maximizes the profit over a long-term planning horizon formulating a mixed-integer linear programming problem. The proposed method has been applied to two case studies to demonstrate its superiority over other existing approaches.
In this paper, a solar hybrid power generation system with chemical looping combustion (CLC) is analyzed. Using concentrated solar thermal energy at about 500℃ as a heat source to drive the endothermic reduction of metal oxide with CH4 in the fuel reactor, and then the metal oxide is transported into the air reactor to be oxidized for regeneration. After that, the flue gas from the air reactor is further drive the gas turbine for power generation. In this paper, the behavior of thermodynamic performance is analyzed. Two important indicators of fuel energy saving ratio (FESR) and exergy efficiency are used to evaluate. The FESR and the exergy efficiency would be expected to reach 34.14% and 49.50%, respectively. At last, the feasibility of the key process was verified by experiments in honeycomb reactor. The oxygen transfer rate and oxygen loss capacity of the reaction process showed exciting performance. Also, the redox stability of oxygen carrier had little changes after repeated cycles.
Over time there have been many examples of failed technology transfer, most often attribute to social opposition based around concerns of impacts on either individuals or the environment more broadly. The same holds true for energy technologies and yet we know in this A + B approach technologies are a central component of achieving a successful transition. Most of this will likely come from a top down approach of politicians, policy makers, industry and academia deciding on the best way forward. However to date, slow progress has shown that many are reluctant to commit the required resources for making the transition and the IPCC report “Global Warming of 1.5°C” highlights how far behind we are on achieving the required carbon mitigation. We suggest that alongside the technological developments it will be critical to acknowledge the role of people power. A bottom up approach to decision making and technological change. To do this we suggest building a global approach to energy literacy will be a critical component for closing the loop and creating action. This will put people at the center of the decision making for identifying the way forward but does so through a systems lens that takes into account the overall sustainability of the system, governance, market operations and the range of technologies and associated infrastructure. We aim to draw on a range of case studies from across China and Australia to illustrate how this might be achieved in practice.
Manufacturing is responsible for approximately one-third of primary energy use and 37% of carbon dioxide emissions globally. As the interest in renewable energy is growing, this study considers the economic feasibility and environmental implications of installing onsite roofmounted solar PV systems on a case study manufacturing facility in five U.S. states (California, Florida, Indiana, New Jersey, and Texas), which have varying levels of solar irradiance, different incentives, solar policies, and manufacturing incentives at both the federal and state level. In these five cases, a combination of high efficiency SunPower solar panels (monocrystalline) with sun tracking technology are considered. The objective of this research is to compare the impact of state incentives and regulatory policies, as well as physical and locational differences, on the economic and environmental performance of high efficiency monocrystalline solar PV panels used for powering manufacturing processes. Using NREL’s System Adviser Model (SAM), common financial metrics such as the economic payback period, Net Present Value (NPV) and Levelized Cost of Energy (LCOE) are investigated considering the federal and local incentive policies for the selected states. Energy Payback Time (EPBT) and Greenhouse Gas emissions (GHG) as common environmental performance metrics for life cycle of PVs are compared for different cases. The results indicate, lower LCOE and positive NPV can be achieved under certain conditions with the economic payback time ranging from 3 to 15 years. EPBT is less than two years for the five selected states with the CO2 equivalent abatement cost ranging from $0.5 – $151 per ton.