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Promoting the use of solar energy resources has always involved the challenges of instability and supply–demand mismatch. The key to solving these issues is to efficiently store and utilize solar energy resources using high-performance heat storage devices. This study designed a high-performance shell-and-tube phase-change thermal storage device and established a numerical model using ANSYS software to summarize the device's dynamic melting law. To verify the accuracy of the numerical simulation, a performance testing platform for the phase-change thermal storage device was built to investigate the impact of various factors, such as the inlet water temperature, inlet water flow rate, type of heat storage, and initial temperature of the device, and to reveal the change law of the device's performance. The results show that the inlet water temperature has the most significant impact on the device's heat storage and release performance. When the device's heat storage or release is used for heating, changing the inlet water flow rate has a weak and limited effect on the device's performance. However, when the device's heat release is used to provide domestic hot water, increasing the make-up water temperature and reducing the inlet water flow rate can significantly improve the device's effective heat release. Furthermore, based on the experimental validation of the model's correctness, this study further simulated and studied the impact of different factors on the device's heat storage process to optimize its structural design and provide technical references for the device's actual operation and installation. The results show that the placement of fins has a negligible effect on the performance of the heat storage device while reducing the fin spacing and increasing the fin thickness can significantly improve the melting efficiency of the phase-change material (PCM). Additionally, the heat storage characteristics of the device are significantly better in the vertical installation mode than in the horizontal installation mode. This study provides theoretical guidance and technical references for the design and use of phase-change thermal storage devices. [ABSTRACT FROM AUTHOR]

Promoting energy efficiency (EE) requirements for new residential buildings has been proven to be an effective way to slow down the rapid increase of energy consumption. Its successful implementation relies significantly on the attitudes and participation of various stakeholders within the industry, yet they are normally taken for granted. This paper explores and reports both the consensus among and the diversity of the attitudes of frontline stakeholders toward future EE requirements in the new residential building sector via a nationwide Delphi questionnaire distributed to 29 institutes and 25 experts. Results indicate that promotion of approximately 30% EE every five years until 2030 is suggested and that 20% EE promotion every five years is the most likely to be achieved. In addition, China should progressively adopt the energy intensity index into the current building EE evaluation system. This paper also gives a detailed description of opinions from frontline stakeholders. The findings are expected to help researchers and policymakers better understand the true attitudes of stakeholders, thereby enabling the formation of a proper outlook for new residential building EE promotion. [ABSTRACT FROM AUTHOR]

Highlights • A multi-criteria evaluation system is proposed for community energy planning. • Both subjective and objective weights are considered for the optimal weight. • An improved grey incidence method is used to evaluate energy planning schemes. • The optimized CCHP is the best scheme for the university campus in this study. Abstract Community energy planning is necessary for sustainable development of energy systems. However, given a series of energy sources and energy utilization technologies, it is crucial to select the optimal energy supply system to obtain the maximum comprehensive benefits. This study attempts to extend a multi-criteria integrated evaluation method that considers the aspects of technology, economy, environment, and society for evaluating the planning schemes of distributed energy supply systems. First, the rank correlation analysis and entropy information method are adopted to obtain subjective and objective weights, respectively. A combination of the maximum entropy principle and the minimized weighed generalized distance to the ideal scheme are employed to obtain optimal weighting coefficients. Second, based on the different priorities of evaluation indexes, the optimal schemes are established based on the improved grey incidence evaluation method, and under the integrated evaluation, the optimized combined cooling/heating and power system is proven to be the best option for the given case study. The results show that the proposed multi-criteria integrated evaluation method is a simple and practical tool for community energy planning. [ABSTRACT FROM AUTHOR]

Abstract: The establishment of energy consumption quota is an important project for promoting the development of building energy efficiency in China. This research focused on the establishment of energy consumption quota of four and five star luxury hotels in Hainan Province, one of the international traveling destinations. Firstly, the theoretical analysis of energy consumption quota included data acquisition, normalization of energy use index and the statistical analysis methods for the calculation of the energy consumption quota. Subsequently, detailed information of 19 hotels plus general energy consumption data of 54 hotels was treated as the sample data for calculating energy consumption quota. According to correlation analysis, energy consumption per unit area was identified to be the most suitable index to represent the energy consumption level, and was combined with the energy consumption normalized by degree-day method to obtain the normalized energy use index (EUInorm). Also, the energy consumption quota interval of four and five star luxury hotel buildings in Hainan in the initial implementation stage was identified as 69.23–96.75kWh/m2 in accordance with comparison of the results calculated by statistical methods. Finally, proposals were put forward about the implementation of building energy consumption quota. [Copyright &y& Elsevier]

Abstract: Accurate energy saving effect evaluation analysis of building energy efficiency retrofit is of benefit to obtain technology optimization and fast return of investment. According to the implement sequence, evaluation methods can be divided into post evaluation and prediction evaluation. The energy saving effect of an air-conditioning system retrofit project was analyzed by these two models respectively. The post evaluation model was built based on the spot test data and a parameter called as Refrigeration Operation Energy saving Effect Ratio (ROEER). The prediction evaluation model was built based on Back-Propagation Artificial Neural Network by the use of MATLAB Neural Network Toolbox. The comparison result between these two kinds of evaluation models match well with each other. These two models can be used to predict and evaluate energy saving effect of air-conditioning system retrofit to further improve the real energy saving effect of building energy efficiency retrofit. [Copyright &y& Elsevier]