scholarly journals Use of the Life Cycle Methodology to Calculate Energy Consumption of Urban Water Cycle: A Case Study of Ordos City

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2393
Author(s):  
Luming Zhou ◽  
Xinghua Xie ◽  
Shiqiang Wu

Water resources and energy constitute two broad categories of resources required for social and economic development. The water-energy nexus has become a focus of research in recent years. Although water resources are closely related to energy systems, the processes involved remain incompletely understood due to the diversity and complexity of energy types, processes, and consumption sectors. This study aimed to accurately calculate the energy demand of water resources and to identify an effective method of improving the energy utilization efficiency of water. The life cycle of water resources was divided into five stages based on the life cycle methodology: (1) extraction, (2) purification, (3) transportation, (4) utilization, (5) sewage treatment. The quantity and characteristics of energy consumed in each stage were studied, and an equation to calculate energy consumption for each stage was proposed. Using the city of Ordos in Northwest China as an example, energy consumption of water resources from 2013 to 2017 was analyzed. The results showed that from 2013 to 2017, energy consumption and per unit energy consumption of water resources in Ordos decreased by 33.3% and 30.6% from 1.62 × 108 kWh to 1.08 × 108 kWh and from 10.11 kWh·m−3 to 7.02 kWh·m−3, respectively. The majority of energy consumption over the entire life cycle of water resources occurred during the utilization stage at a proportion of total energy consumed of ~95%. Use of water for thermal power generation was identified as the single largest consumer of energy and, therefore, has the greatest potential for energy saving.

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2275
Author(s):  
Zhuo Wang ◽  
Yanjie Zhang ◽  
Tao Wang ◽  
Bo Zhang ◽  
Hongwen Ma

The reverse osmosis method has developed extremely rapidly in recent years and has become the most competitive seawater desalination technology in the world, and it has been widely used in all aspects. Large-scale reverse osmosis desalination plants cannot provide fresh water resources in areas with insufficient water resources and limited space. Therefore, this paper proposes a research plan for a small seawater desalination device based on reverse osmosis, which is mainly suitable for handling emergencies, disaster relief, desert areas and outdoor activities and other needs for timely freshwater resources. It mainly includes pretreatment modules, a reaction infiltration module, a post-processing module and an energy supply module. Detailed design calculations are carried out for the small-scale reverse osmosis membrane system, including the selection and quantity and arrangement of membranes. Subsequently, the one-stage two-stage small-scale reverse osmosis membrane system was modeled, and its energy consumption was analyzed theoretically from the perspectives of specific energy consumption and energy utilization efficiency; the main influencing factors were clarified, and the optimal recovery rate for system operation was determined to be 20%–30%. Finally, an experimental prototype was built to conduct relevant experiments to determine the influence trend of pressure, temperature, concentration, and flow rate on the operating performance of the reverse osmosis system.


2015 ◽  
Vol 764-765 ◽  
pp. 1154-1158
Author(s):  
Yu Sheng Chang

The sewage comes from buildings is drained into public sewers. The sewage is then treated in a sewage treatment plant to meet the sanitation standards before being discharged to the water cycle in nature. The sewage treatment process consumes energy and produce CO2. In this research, the idea of streamlined life cycle assessment was applied. The CO2 emission of sewage treatment was assessed from direct energy consumption of four major sewage treatment plants in Taiwan. The results show that the unit CO2 emission of sewage treatment calculated from four plants is 0.174 kg-CO2/m3. The CO2 emission at in-plant sewage treatment stage takes more than 95% of total CO2 emission for most plants. The results suggest that CO2 emission of sewage treatment can be calculated from energy consumption at in-plant sewage treatment stage to simplify the calculation. This database will be important reference for water resource research.


1992 ◽  
Vol 27 (2) ◽  
pp. 221-238 ◽  
Author(s):  
W. Ripl

Abstract Densely populated urban areas, which have developed over the last century, depend heavily on centralized water supply, sewage treatment plants, and hydroelectric or thermal power generation with vast demand of cooling water. Considerable areas have been drained or sealed, and the short-circuited water cycle has been distorted. Large rivers have been converted to shipping canals with the permanent risk of accidental pollution. Technical means such as sewage treatment, air filters, emission control and lake and soil restoration measures have contributed to correct the environmental damage. However, a balance sheet for irreversible matter losses (mainly base cation charges) from the urbanized areas and the surrounding landscape into the sea shows ever-increasing trends. These losses are destabilizing the ecosystems. In this paper, management of the water cycle in urban areas, together with the coupled matter cycles, is discussed. Particular reference is given to Metropolitan Berlin, with a network of shipping canals, which move biologically treated waste, containing base cations and nutrients to the surrounding rural areas. This could create manageable productive wetlands and re-establish soil fertility. At the same time, the natural cooling system close to the urban areas will be improved by providing more areas with permanent vegetation. In addition, reduction of the present large oscillations of the groundwater table, resulting from groundwater pumping and its recharge with less polluted surface water, is contemplated. The widely used shoreline infiltration of the Havel River should then be eliminated and the severe damage of the littoral vegetation in large sections of the Havel River system be avoided.


2021 ◽  
pp. 1-18
Author(s):  
Jiahang Yuan ◽  
Yun Li ◽  
Xinggang Luo ◽  
Lingfei Li ◽  
Zhongliang Zhang ◽  
...  

Regional integrated energy system (RIES) provides a platform for coupling utilization of multi-energy and makes various energy demand from client possible. The suitable RIES composition scheme will upgrade energy structure and improve integrated energy utilization efficiency. Based on a RIES construction project in Jiangsu province, this paper proposes a new multi criteria decision-making (MCDM) method for the selection of RIES schemes. Because that subjective evaluation on RIES schemes benefit under criteria has uncertainty and hesitancy, intuitionistic trapezoidal fuzzy number (ITFN) which has the better capability to model ill-known quantities is presented. In consideration of risk attitude and interdependency of criteria, a new decision model with risk coefficients, Mahalanobis-Taguchi system and Choquet integral is proposed. Firstly, the decision matrices given by experts are normalized, and then are transformed to minimum expectation matrices according to different risk coefficients. Secondly, the weights of criteria from different experts are calculated by Mahalanobis-Taguchi system. Mobius transformation coefficients based on interaction degree are to calculate 2-order additive fuzzy measures, and then the comprehensive weights of criteria are obtained by fuzzy measures and Choquet integral. Thirdly, based on group decision consensus requirement, the weights of experts are obtained by the maximum entropy and grey correlation. Fourthly, the minimum expectation matrices are aggregated by the intuitionistic trapezoidal fuzzy Bonferroni mean operator. Thus, the ranking result according to the comparison rules using the minimum expectation and the maximum expectation is obtained. Finally, an illustrative example is taken in the present study to make the proposed method comprehensible.


2015 ◽  
Vol 1092-1093 ◽  
pp. 1597-1600
Author(s):  
Zhong Hua Wang ◽  
Xin Ye Chen

The need to reduce carbon emission in Heilongjiang Province of China is urgent challenge facing sustainable development. This paper aims to make explicit the problem-solving of carbon emission to find low carbon emission ways. According to domestic and foreign literatures on estimating and calculating carbon emissions and by integrating calculation methods of carbon emissions, it was not possible to consider all of the many contributions to carbon emissions. Calculation model of carbon emissions suitable to this paper is selected. The carbon emissions of energy consumption in mining industry are estimated and calculated from 2005 to 2012, and the characteristics of carbon emission are analyzed at the provincial level. It makes the point that carbon emissions of energy consumption in mining industry can be reduced when we attempt to alter energy consumption structure, adjust industrial structure and improve energy utilization efficiency.


2014 ◽  
Vol 881-883 ◽  
pp. 653-658 ◽  
Author(s):  
Yong Qiang Xiong ◽  
Ben Hua

In this paper, a cryogenic air separation process with LNG cold energy utilization is proposed to produce liquid nitrogen and high pressure pure oxygen gas economically. To reduce the electric energy consumption of air separation products, liquid nitrogen have been produced by condensing the separated pure nitrogen gas with LNG cold energy utilization, and the recycled nitrogen is served to transfer cold energy from LNG stream to cool off air stream in the proposed cryogenic air separation process. The specifications of streams and the major equipments of the air separation process are simulated with Aspen Plus software and the main parameters analysis are performed. The results show that the energy consumption of the proposed air separation process with LNG cold energy utilization decreased about 58.2% compared with a conventional cryogenic air separation process. The compressed pressure of recycled nitrogen has a big impact on the cost of air separation products and utilization efficiency of LNG cold energy. The LNG cold energy could be fully utilized when the recycled nitrogen has been compressed to above 6.5MPa.


2014 ◽  
Vol 953-954 ◽  
pp. 890-895
Author(s):  
Hui Min Li ◽  
Cun Bin Li ◽  
Zhan Xin Ma

In recent years, with the rapid economic growth, the demand on the amount of energy in China is increasing. So the problem of how to improve the energy utilization efficiency and save energy consumption has to be tackled. The traditional CCR model and BCC model used in the study of provincial energy efficiency do not take the impact of technological progress into consideration. Therefore, the paper uses the generalized DEA method to research the energy utilization efficiency of China’s 29 provinces, that is, to evaluate and analyze the energy utilization efficiency by selecting the capital stock, employment and total energy consumption of China’s provinces as input factors and GDP, per capital GDP as output factors, and then draw tables showing each province’s change of average annual overall efficiency and the pure technology changes, and finally analyze the regularities underlying these changes.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3319 ◽  
Author(s):  
Liangxiong Wei ◽  
Weijie Sun ◽  
Haixiang Chen ◽  
Ping Yuan ◽  
Feng Yin ◽  
...  

With the quick development of Internet of Things (IoT), one of its important supporting technologies, i.e., wireless sensor networks (WSNs), gets much more attention. Neighbor discovery is an indispensable procedure in WSNs. The existing deterministic neighbor discovery algorithms in WSNs ensure that successful discovery can be obtained within a given period of time, but the average discovery delay is long. It is difficult to meet the need for rapid discovery in mobile low duty cycle environments. In addition, with the rapid development of IoT, the node densities of many WSNs greatly increase. In such scenarios, existing neighbor discovery methods fail to satisfy the requirement in terms of discovery latency under the condition of the same energy consumption. This paper proposes a group-based fast neighbor discovery algorithm (GBFA) to address the issues. By carrying neighbor information in beacon packet, the node knows in advance some potential neighbors. It selects more energy efficient potential neighbors and proactively makes nodes wake up to verify whether these potential neighbors are true neighbors, thereby speeding up neighbor discovery, improving energy utilization efficiency and decreasing network communication load. The evaluation results indicate that, compared with other methods, GBFA decreases the average discovery latency up to 10 . 58 % at the same energy budget.


2014 ◽  
Vol 522-524 ◽  
pp. 1670-1674
Author(s):  
Qian Dong

Industrialization brings great pressure to the construction of urban ecological environment. Yinchuan of Ningxia, located in the northwest economic underdeveloped regions, has good energy supply conditions. Unreasonable energy consumption structure and energy utilization way leads to massive energy consumption. Give some prediction for the possible future energy demand mode, and give suggestion on aspects of the urban heating and the development of energy industry planning.


Author(s):  
Zhen Xian Lin ◽  
Lin Fu

With the process acceleration of China’s energy conservation and the full development of the market economy, the environmental protection is to coexist with the power plants’ benefits for thermal power plants. Relative to the traditional mode named “determining power by heat”, it is not adequate that the heating demand is only to be met, the maximizations of economy benefits and social benefits are also demanded. At present, several large-scale central heating modes are proposed by domestic and foreign scholars, such as the parallel arrangement and series arrangement of heating system for the traditional heating units and NCB heating units (NCB heating unit is a new condensing-extraction-backpressure steam turbine and used to generate the power and heat, it has the function of extraction heating turbine at constant power, back pressure turbine or extraction and back pressure heating turbine and extraction condensing heating turbine.), and running mode with heating units and absorbed heat pumps, and so on. Compare and analyze their heating efficiency, heating load, heating area, power generation, and the impact on the environment. The best heating mode can be found under the different boundary conditions, it can be used to instruct the further work. The energy utilization efficiency will be further improved.


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