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Low-carbon travel is an important part of low-carbon cities and low-carbon transportation, and low-carbon transportation is an inevitable choice to slow down the growth of carbon emissions in China. All countries in the world are actively promoting new energy vehicles and attach great importance to the application of the new energy industry in urban transportation. Commuting is an important part of urban life, and the choice of travel behavior has an important impact on traffic and environmental protection. Taking the Xi'an metropolitan area as an example, this paper expounds on the integrated development path of the industrial chain of new energy + travel in the metropolitan area and clarifies the energy transformation model of the integrated development of low-carbon transportation and energy. From the perspective of green and low-carbon, 1000 commuters were interviewed using a questionnaire survey, and the cumulative prospect model was used to verify the internal mechanism affecting commuters in metropolitan areas to choose new energy commuting. The results of the study show that new energy transportation modes play an important role in the low-carbon economy, and under different scenarios and assumptions, there are significant differences in the cumulative prospect values of the subway, new energy buses and fuel private cars, and corresponding optimization measures are proposed to increase the proportion of new energy commuting trips. The results will help further promote the development of a low-carbon economy and energy integration in the field of transportation and provide a reference for the sustainable development of public transportation. [ABSTRACT FROM AUTHOR]

The exploitation and utilization of shallow geothermal energy are of great significance to realizing China's "double carbon" goal and promoting a green economy and social development. However, many projects using ground source heat pumps to exploit shallow geothermal energy have disrupted the thermal balance of the geothermal field due to insufficient preliminary research, affecting the sustainable utilization of shallow geothermal energy. Therefore, a 3D groundwater–thermal coupling model was established in this paper using the geotemperature data of a ground source heat pump system in Xi'an. This study investigated the response characteristics of the groundwater–thermal system to the ground source heat pump system using the numerical simulation method and discussed the optimal layout scheme of the system on this basis. After years of simulation, it was found that long-term operation of the ground source heat pump system under actual operation produces "cold accumulation". In addition to artificial intervention of the groundwater flow field, the effects of the system operating parameters and layout settings are also investigated to alleviate this cold accumulation. The results show that changing the operating parameters so that the heat transfer is the same in winter and summer, cross-locating the cooling holes with the heating holes, and placing multiple pumping and recharge wells downstream can alleviate the cold accumulation in the heat exchange zone. The results of this numerical simulation study provide an important reference for solutions to mitigate the accumulation of ground cold and heat in developing shallow geothermal energy using borehole heat exchangers and to suppress the downstream geotemperature disturbance via the ground source heat pump system. [ABSTRACT FROM AUTHOR]

In the age of the digital economy, the data center is the most crucial piece of infrastructure. The issue of the excessive power consumption of a data center's cooling system needs to be addressed as the national objective of "peak carbon and carbon neutrality" is increasingly promoted. In this study, a microchannel-separated heat pipe-cooling system with evaporative condensation is introduced. The system may switch between three modes of operation in response to changes in outdoor air quality parameters, thereby maximizing the utilization of natural cooling sources while lowering data centers' cooling costs. The purpose of this paper is to analyze the energy-saving potential of the hybrid system through experimental tests. The results show that 114.4% is the ideal liquid-loading rate for the heat pipe system. Under working conditions in Xi'an, the annual operating hours of the three modes accounted for 47.2%, 6.1%, and 46.7%. The hybrid cooling system may save 62.04% of the energy used annually compared to the standard cooling system and the cooling system in the server room thanks to its yearly average COP of 9.43. [ABSTRACT FROM AUTHOR]

The variability and inhomogeneity of solar energy limits the development of solar heating systems (SHS) in many fields. In order to improve the utilization efficiency of SHS, this paper takes three typical cities (Xi'an, Dunhuang, Lhasa) as the research object, studies the operation state of SHS in student dormitory buildings, and puts forward a corresponding optimization strategy. The research shows that the reduction of water supply temperature will improve the operation efficiency and energy saving effect of a spontaneous combustion heat pump and that there is an optimal volume of heat storage water tank (HSWT), which can make the energy saving effect of SHS run better. The optimization of the SHS shows the water supply temperature is 35 °C, and the optimal volume of HSWT is 15 m3 in the "Resource-general area (Ⅲ)" represented by Xi'an, 25 m3 in the "Resource-rich area (Ⅱ)" represented by Dunhuang, and 40 m3 in the "Resource-richer area (Ⅰ)" represented by Lhasa. With the increase in the abundance of solar energy resources in the region, the optimal volume of HSWT also increases. Meanwhile, the solar energy contribution rate of the three regions in descending order is 61.3% (Lhasa), 32.8% (Dunhuang), and 25.9% (Xi'an). After optimization, the contribution of SHS increased by about 5%. The research results will help improve the efficiency of SHS in cold areas of China and make the system more efficient and energy efficient during operation. [ABSTRACT FROM AUTHOR]

Due to the increase in environmental problems and air pollution during the heating period, it is important to promote clean heating in cold regions, thereby meeting the heating demand in a green manner. In order to allocate resources more effectively and facilitate the consumption of renewable energy, this paper designs an integrated heating system that incorporates geothermal energy into the framework of an integrated energy system of electricity, heating, and gas. An analysis of the environmental and economic benefits indicates that the system reduces pollutant emissions and decreases the cost of urban heating. Using an example of central heating of residential buildings in Xi'an, the paper conducts a scenario analysis based on the gas peak-shaving ratio and the ratio of geothermal heating loads to basic heating loads. The results demonstrate that the environmental and economic benefits of the integrated heating system are higher compared to central heating using coal-fired boilers. In addition, this paper conducts a sensitivity analysis of the heat source to the price factors and the load ratios. The results show that the operating costs of the integrated heating system are most sensitive to the natural gas price and the gas peak-shaving ratio. Therefore, an optimum natural gas peak-shaving ratio can be determined. [ABSTRACT FROM AUTHOR]