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Abstract In a pressurized water reactor (PWR), the control rod drop analysis is crucial for the reactor safety and the integrity of core structure. Especially under a seismic condition, the horizontal deflections of the reactor system could cause impact between the control rods and the guide thimbles, and then the resulting frictional forces can significantly increase the scram time and intensify mechanical interaction at the absorber rod cladding and spider springs. The CRDAC code is a control rod scram analysis tool developed by China Nuclear Power Technology Research Institute (CNPRI). In a previous work, Liu et al., 2013 , Li et al., 2013 studied the transverse behavior and the fluid-structure interaction of the whole movement system based on this code. Liu calculated the scram time of a 12ft fuel assembly under the Wenchuan earthquake wave. Huang et al. (2014) proposed a flow model to describe the effect of the flow field parameters on the scram time under the operation condition. This paper presents the seismic analysis method based on the CRDAC code which developed by China Nuclear Power Technology Research Institute (CNPRI). Both the scram time and the seismic response have been calculated, such as the maximum pressure in the guide thimble, impact forces to the spider spring, and friction forces to the absorber rod. According to the design requirements of the third-generation nuclear power plants, safety shutdown earthquake (SSE) and operating basis earthquake (OBE) for the horizontal response need to satisfy 0.3 g and 0.15 g, respectively. Therefore, the maximum accelerations of both the input and the initial horizontal deformation of a fuel assembly have been taken into account in this paper. After several sensitive analyses, it is found that the CRDAC code is a powerful tool for the design of control rods and fuel assemblies.

Abstract Technological progress is an effective way to improve electricity efficiency. Due to the existence of the rebound effect, it is of great significance to optimize the technical power saving policy by examining the rebound effect caused by different technological progress paths.Based on the panel data of electricity industry in 30 provinces of China from 1997 to 2013, this paper systematically examines the rebound effects of electricity consumption under the two sources of technological progress, namely independent innovation and technology import. Then, it discusses the impact of coal-electricity linkage policy. The empirical results are as follows: (1) without considering rebound effect, independent innovation significantly promotes electricity conservation, while the effects of technology import is not obvious; (2) when considering the rebound effect, electricity price declining driven by independent innovation is not conducive to electricity saving, while electricity price declining driven by technology import has an electricity-saving effect; (3)The coal-electricity linkage policy that began in 2004 not only reduced the rebound effect by increasing the flexibility of electricity prices to a certain extent and improved the electricity-saving effect of independent innovation, but also reduced the electricity-saving effect of technology import.

The promotion of electric vehicles (EVs) is an important measure for dealing with climate change and reducing carbon emissions, which are widely agreed goals worldwide. Being an important operating mode for electric vehicle charging stations in the future, the integrated photovoltaic and energy storage charging station (PES-CS) is receiving a fair amount of attention and discussion. However, how to optimally configure photovoltaic and energy storage capacity to achieve the best economy is essential and a huge challenge to overcome. In this paper, based on the historical data-driven search algorithm, the photovoltaic and energy storage capacity allocation method for PES-CS is proposed, which determines the capacity ratio of photovoltaic and energy storage by analyzing the actual operation data, which is performed while considering the target of maximizing economic benefits. In order to achieve the proposed capacity allocation, the method is as follows: First, the economic benefit model of the charging stations is established, taking the net present value and investment payback period as evaluation indicators; then, by analyzing the operation data of the existing charging station with the target of maximizing economic benefits, the initial configuration capacity is obtained; finally, the capacity configuration is verified through a comprehensive case analysis for the actual operation data. The results show that the capacity configuration obtained through the data analysis features an optimized economic efficiency and photovoltaic utilization. The proposed method can provide a theoretical and practical basis for newly planned or improved large-scale charging stations.

Since the official launch of the Belt and Road Initiative (BRI) in 2013, China and the BRI countries have been working for the implementation of certain environmental measures to make the BRI project green and clean. For this purpose, China and the BRI countries have planned to implement certain environmental measures. Although China can efficiently implement these measures, most of the BRI countries face technological deficiencies and lack of proper environmental plannings. To tackle these deficiencies, the BRI countries can import environmental technology from China. Moreover, they can communicate their environmental protection policies with China for better policy guidance. The current study, therefore, aims to examine whether the BRI countries’ import of environmental technology from China can reduce carbon emissions in these countries. Moreover, it also examines that whether these countries should follow the environmental policy and the import policy of China or they should follow the six European countries (EU-6) with minimum carbon emissions intensity. This study considers a sample of 88 selected BRI countries (BRI-88) for the period 2001–2019. The results obtained with β convergence (based on the panel quantile regression model) suggest that not all the BRI countries but only the BRI countries with relatively higher carbon emissions intensity can significantly reduce their average carbon emissions intensity by importing environmental technology from China. Moreover, BRI countries can follow the environmental policy of China which is more feasible for them. However, regarding the environmental goods import policy, BRI countries can follow both China and the EU-6.

AbstractUsing a low supply water temperature in heating conditions and a high water temperature during cooling can increase energy efficiency, use renewable energy sources, and provide a comfortable and healthy indoor climate. High temperature cooling and low temperature heating is achieved by reducing temperature difference in heat trans er and energy transportation process. The losses in temperature difference can be classified into three types: by heat/moisture exchange; by energy transportation through air/water circulation; by indoor terminal that releases heat/cooling to indoor condit oned space. The air handling process of HVAC system and indoor terminals are the key factor of reducing temperature differen e.Aiming at the losses in HVAC system, Annex 59, titled High Temperature Cooling & Low Temperature Heating in Buildings, is a new international cooperative work under the framework of International Energy Agency (IEA) Energy in Buildings and Communities (EBC). This paper introduc s the background, scope, objective, structure and deliverables of Annex 59. Annex 59 will try to present a new perspective and a new concept to analyze HVAC system in buildings. The goal of the Annex is to build up new concept of analyzing HVAC system from the perspective of reducing mixture loss and transfer loss and th n apply it in high temperature cooling and low temperature heating system.

In light of the increasing number of electric vehicles (EV), disorderly charging in mountainous cities has implications for the stability and efficient utilization of the power grid. It is a roadblock to lowering carbon emissions. EV aggregators are a bridge between EV users and the grid, a platform to achieve energy and information interoperability, and a study of the orderly charging of EVs to reach carbon emission targets. As for the objective function, the EV aggregator considers the probability of EV charging access in mountainous cities, the SOC expectation of EV users, the transformer capacity constraint, the charging start time, and other constraints to maximize revenue. Considering the access probability of charging for users in mountainous cities, the optimized Lagrange relaxation method is used to solve the objective function. The disorderly charging, centralized optimized charging, and decentralized optimized charging modes are investigated using simulation calculations. Their load profiles, economic benefits, and computational efficiency are compared in three ways. Decentralized optimal charging using the Lagrange relaxation method is shown to be 50% more effective and to converge 279% faster than centralized optimal charging.

Forecasting of energy consumption has always been an essential part of energy planning and policy. This paper presents grey model (GM), multiple regression model (MRM) and the integration model of grey model and multiple regression model (IGMMRM) to forecast the number and trend of energy consumption in Zhejiang. The three prediction models established are the highly accurate forecasting, but the combination model was found to be the best model which can overcome some defects of single model such as GM and MRM when mining information. Using IGMMRM, energy consumption of Zhejiang will be almost 0.19 billion tons coal equivalent in 2010 and over 0.3 billion tons coal equivalent in 2015, respectively. It is urgent that level of sustainable utilization for energy should be further improved in Zhejiang.

Abstract As one of the chemical looping combustion (CLC) technologies, separated gasification-CLC (SG-CLC) can realize the carbon separation during coal combustion process with low degradation of oxygen carrier and high performances. In order to realize the auto-thermal operation of the constructed pilot-scale SG-CLC unit, some oxygen was added into the gasification agent to compensate the endothermic gasification of coal using steam. The combustion performances of SG-CLC unit were investigated under different conditions with variables of reaction temperature, coal feed rate, steam mass flow, oxygen flow and type of loosen gas. Ten conditions were designed and conducted to study the effects of variables on the CLC performances. According to the temperature curves, auto-thermal operation was achieved in seven of these tests. Carbon capture efficiencies under auto-thermal operation were almost higher than 97% and the oxygen demands in these test were less than 4.70%. The peak value of solid fuel conversion was 93.91% at 930 °C while the minimum was 87.36% at 830 °C under auto-thermal conditions. The performances demonstrated that the SG-CLC system could offer great possibility for its commercial application under auto-thermal conditions. Furthermore, some measures were put forward to optimize the operation of this SG-CLC system.

With the rapid development of building technology, transparent envelope is more and more widely used, which makes the indoor environment of buildings more and more affected by solar radiation. However, the effects of solar radiation are not included in the PMV model. The Corrected Predicted Mean Vote (CPMV) model considering solar radiation was previously proposed and verified in northern China. In order to expand the applicability of the CPMV model to the hot summer and cold winter (HSCW) zone of southern China, a field study was conducted in an office building in Nanjing. A total of 686 valid questionnaires were recovered during the surveys in two summers in 2019 and 2020. The results show that the evaluation value of CPMV is highly consistent with the actual thermal sensation vote (TSV) when the corrected operative temperature is below 30 °C. However, when the corrected operative temperature is above 30 °C, the CPMV value is higher than TSV, because it underestimates the tolerance of human body to the hot environment in Nanjing. The thermal neutral temperature is 26.12 °C (CPMV) and 26.28 °C (TSV) respectively, which is higher than that in winter and summer in northern China. This study fills the blank in the application of CPMV model in southern China. The CPMV model can accurately evaluate the thermal comfort of indoor environment affected by solar radiation, which is worthy of promotion and application to other types of buildings and areas.