Integration of Low-level Waste Heat Recovery and Liquefied Nature Gas Cold Energy Utilization

Two novel thermal cycles based on Brayton cycle and Rankine cycle are proposed, respectively, which integrate the recovery of low-level waste heat and Liquefied Nature Gas （LNG） cold energy utilization for power generation. Cascade utilization of energy is realized in the two thermal cycles, where low-level waste heat,low-temperature exergy and pressure exergy of LNG are utilized efficiently through the system synthesis. The simulations are carried out using the commercial Aspen Plus 10.2, and the results are analyzed. Compared with the conventional Brayton cycle and Rankine cycle, the two novel cycles bring 60.94% and 60% in exergy efficiency, respectively and 53.08% and 52.31% in thermal efficiency, respectively.

Improving energy utilization efficiency of electrical discharge milling in titanium alloys machining

Electrical discharge milling(ED-milling) can be a good choice for titanium alloys machining and it was proven that its machining efficiency can be improved to compete with mechanical cutting. In order to improve energy utilization efficiency of ED-milling process, unstable arc discharge and stable arc discharge combined with normal discharge were implemented for material removal by adjusting servo control strategy. The influence of electrode rotating speed and dielectric flushing pressure on machining performance was investigated by experiments. It was found that the rotating of electrode could move the position of discharge plasma channel, and high pressure flushing could wash melted debris out the discharge gap effectively. Both electrode rotating motion and high pressure flushing are contributed to the improvement of machining efficiency.

Dietary supplementation with xylooligosaccharides and exogenous enzyme improves milk production,energy utilization efficiency and reduces enteric methane emissions of Jersey cows

Background Sustainable strategies for enteric methane(CH_(4))mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure.The present study aimed to investigate the effects of dietary xylooligosaccharides(XOS)and exogenous enzyme(EXE)supplementation on milk production,nutrient digestibility,enteric CH_(4) emissions,energy utilization efficiency of lactating Jersey dairy cows.Forty-eight lactating cows were randomly assigned to one of 4 treatments:(1)control diet(CON),(2)CON with 25 g/d XOS(XOS),(3)CON with 15 g/d EXE(EXE),and(4)CON with 25 g/d XOS and 15 g/d EXE(XOS+EXE).The 60-d experimental period consisted of a 14-d adaptation period and a 46-d sampling period.The enteric CO_(2)and CH_(4) emissions and O2 consumption were measured using two GreenFeed units,which were further used to determine the energy utilization efficiency of cows.Results Compared with CON,cows fed XOS,EXE or XOS+EXE significantly(P<0.05)increased milk yield,true protein and fat concentration,and energy-corrected milk yield(ECM)/DM intake,which could be reflected by the significant improvement(P<0.05)of dietary NDF and ADF digestibility.The results showed that dietary supplementation of XOS,EXE or XOS+EXE significantly(P<0.05)reduced CH_(4) emission,CH_(4)/milk yield,and CH_(4)/ECM.Furthermore,cows fed XOS demonstrated highest(P<0.05)metabolizable energy intake,milk energy output but lowest(P<0.05)of CH_(4) energy output and CH_(4) energy output as a proportion of gross energy intake compared with the remaining treatments.Conclusions Dietary supplementary of XOS,EXE or combination of XOS and EXE contributed to the improvement of lactation performance,nutrient digestibility,and energy utilization efficiency,as well as reduction of enteric CH_(4) emissions of lactating Jersey cows.This promising mitigation method may need further research to validate its long-term effect and mode of action for dairy cows.

Current Situation and Suggestions for Energy Utilization of Agricultural Waste in Hubei Province

Energy utilization is high-value use pattern of agricultural waste, and is main development direction of agricultural biomass energy industry in China. Planting and breeding industry in Hubei Province occupies important position in whole country. Agricultural waste resources are rich, and it has huge potential for developing agriculturel biomass energy. By statistical data during 2000 -2011, we analyzed current situation and problem for energy utilization of agricultural waste in Hubei Province, and put forward several countermeasures and suggestions, vigorously promoting energy utilization of agricultural waste.

Guangdong Dapeng LNG cold energy utilization-C_2++ extraction process integration

This paper makes a study of some technical and engineering aspects by using C2 ＋ hydrocarbon separation facility at Guangdong Dapeng liquefied natural gas （GDLNG） terminal. In the C2＋ hydrocarbon extraction process, the cold energy contained in LNG will be utilized. In order to ensure the optimum operating conditions of the temlinal and C2 ＋ hydrocarbon extraction facility by optimizing the current operating processes of the terminal, the C2 ＋ hydrocarbon extraction facility construction plan is proposed. We conducted numerous calculations and simulations using such specific analysis software as PRO II 〈 version 7.0 〉. Additionally available flow data are used to verify the cyclic send-out rates from the terminal, thus establishing the current and future projected load factors. This study is intended to make sure that GDLNG can continue to supply gas via the pipeline system safely without interruptions and most significantly solves the effects of flow fluctuations at the terminal gasification send-out facility on the hydrocarbons extraction, ensuring optimum pipeline operations and ensuring safe and effective means for such C2＋ hydrocarbons extraction process as well. At the same time, the terminal is also in the optimum operation condition. This is very significant to the terminal safety operation and the energy conservation and emission reduction.

Progress and Development Strategy of Biomass Energy Utilization Technologies in China

I. Preface Biomass includes the residues of agriculture, forest and stock breeding, as well as straw, algae and energy crops. In its broad meaning, biomass is a kind of organic matter produced by the photosynthesis of plants, which is not only renewable, but also contains plentiful energy.

A Novel Process for Natural Gas Liquids Recovery from Oil Field Associated Gas with Liquefied Natural Gas Cryogenic Energy Utilization

A novel process to recovery natural gas liquids from oil field associated gas with liquefied natural gas (LNG)cryogenic energy utilization is proposed.Compared to the current electric refrigeration process,the proposed process uses the cryogenic energy of LNG and saves 62.6%of electricity.The proposed process recovers ethane, liquid petroleum gas(propane and butane)and heavier hydrocarbons,with total recovery rate of natural gas liquids up to 96.8%.In this paper,exergy analysis and the energy utilization diagram method(EUD)are used to assess the new process and identify the key operation units with large exergy loss.The results show that exergy efficiency of the new process is 44.3%.Compared to the electric refrigeration process,exergy efficiency of the new process is improved by 16%.The proposed process has been applied and implemented in a conceptual design scheme of the cryogenic energy utilization for a 300 million tons/yr LNG receiving terminal in a northern Chinese harbor.

Clean Processing and Utilization of Coal Energy

The dominant status of coal on the energy production and consumption structure of China will not be changed in the middle period of this century. To realize highly efficient utilization of coal,low pollution and low cost are great and impendent tasks. These difficult problems can be almost resolved through establishing large-scale pithead power stations using two-stage highly efficient dry coal-cleaning system before coal burning,which is a highly efficient,clean and economical strategy considering the current energy and environmental status of China. All these will be discussed in detail in this paper.

Metagenomics reveals contrasting energy utilization efficiencies of captive and wild camels(Camelus ferus)

Captive conditions can affect the symbiotic microbiome of animals.In this study,we compared the structural and functional differences of the gastrointestinal microbiomes of wild Bactrian camels(Camelus ferus)between wild and captive populations,as well as their different host energy utilization performances through metagenomics.The results showed that wild-living camels harbored more microbial taxa related to the production of volatile fatty acids,fewer methanogens,and fewer genes encoding enzymes involved in methanogenesis,leading to higher energy utilization efficiency compared to that of captive-living camels.These findings suggest that the wild-living camel fecal microbiome demonstrates a series of adaptive characteristics that enable the host to adjust to a relatively barren field environment.Our study provides novel insights into the mechanisms of wildlife adaptations to habitats from the perspective of the microbiome.

The uniqueness and superiority of energy utilization in yaks compared with cattle in the highlands:A review

Yaks living on the Qinghai-Tibetan Plateau for a long time have evolved a series of mechanisms to adapt to the unique geographical environment and climate characteristics of the plateau.Compared with other ruminants,yaks have higher energy utilization and metabolic efficiency.This paper presents possible mechanisms responsible for the efficient energy utilization,absorption and metabolism resulting from the unique evolutionary process of yaks.It is hoped that the information discussed in this review will give a better insight into the uniqueness and superiority of yaks in regards to energy metabolism and utilization compared with cattle and open new avenues for the targeted regulation of energy utilization pathways of other ruminants.

Co-Harvest Phase-Change Enthalpy and Isomerization Energy for High-Energy Heat Output by Controlling Crystallization of Alkyl-Grafted Azobenzene Molecules

Photoisomerization-induced phase change are important for co-harvesting the latent heat and isomerization energy of azobenzene molecules.Chemically optimizing heat output and energy delivery at alternating temperatures are challenging because of the differences in crystallizability and isomerization.This article reports two series of asymmetrically alkyl-grafted azobenzene(Azo-g),with and without a methyl group,that have an optically triggered phase change.Three exothermic modes were designed to utilize crystallization enthalpy(△H_(c))and photothermal(isomerization)energy(△H_(p))at different temperatures determined by the crystallization.Azo-g has high heat output(275-303 J g^(-1))by synchronously releasing△H_(c)and△H_(p)over a wide temperature range(-79℃to 25℃).We fabricated a new distributed energy utilization and delivery system to realize a temperature increase of 6.6℃at a temperature of-8℃.The findings offer insight into selective utilization of latent heat and isomerization energy by molecular optimization of crystallization and isomerization processes.

Performances of an air thermal energy utilization system developed with fan-coil units in large-scale plastic tunnels covered with external blanket

To improve the problem of low temperature at night in winter due to the lack of thermal storage in large-span plastic tunnels,an air thermal energy utilization system(ATEUS)was developed with fan-coil units to heat a large-scale plastic tunnel covered with an external blanket(LPTEB)on winter nights.The ATEUS was composed of nine fan-coil units mounted on top of the LPTEB,a water reservoir,pipes,and a water circulation pump.With the heat exchange between the air and the water flowing through the coils,the thermal energy from the air can be collected in the daytime,or the thermal energy in the water can be released into the LPTEB at night.On sunny days,the collected thermal energy from the air in the daytime(E_(c))and released thermal energy at night(E_(r))were 0.25-0.44 MJ/m^(2) and 0.24-0.38 MJ/m^(2),respectively.Used ATEUS as a heating system,its coefficient of performance(COP),which is the ratio of the heat consumption of LPTEB to the power consumption of ATEUS,ranged from 1.6-2.1.A dynamic model was also developed to simulate the water temperature(T_(w)).Based on the simulation,E_(c) and E_(r) on sunny days can be increased by 60%-73%and 38%-62%,respectively,by diminishing the heat loss of the water reservoir and increasing the indoor air temperature in the period of collecting thermal energy.Then,the COP can reach 2.6-3.8,and the developed ATEUS can be applied to heating the LPTEB in a way that conserves energy.

China' s Fundamental Research in Energy Utilizations and Environment

The progress in the science of energy utilizations will act crucial effect on the developments of energy science and technology, which will then promote social and economical developments and fulfill requirements for the national strategic objectives. For the sake of sustainable development, a harmonious blend of energy utilizations and environment considerations will become one of the vital topics in the future research area of energy science. It is suggested that clean and high-efficiency utilization of traditional or fossil energy resources, fundamental investigations on the energy and environment theory, renewable energy utilizations, and the development of nuclear energy are selected as priority research areas during the period of the Tenth Five-year Plan of China, according to the development trend of the world energy science and the research background of Chinese energy science, It is expected to promote the interdisciplinary investigations in the science of energy utilizations and provide scientific and technological supports for the development of related advanced high technologies,

Optimal Design of Water Utilization Network with Energy Integration in Process Industries

Effective utilization of water and energy is the key factor of sustainable development in process industries, and also an important science and technology problem to be solved in systems engineering. In this paper,two new methods of optimal design of water utilization network with energy integration in process industries are presented, that is, stepwise and simultaneous optimization methods. They are suitable for both single contaminant and multi-contaminant systems, and the integration of energy can be carried out in the whole process system, not only limited in water network, so that energy can be utilized effectively. The two methods are illustrated by case study.

The Develoyment Program of Energy Conservation and Comprehensive Utilization 2005-2007

Jointly published by 14 Department headed by Standardization Administraion ofChina(SAC) Subtitle: China will formulate and reformulate 926 standards for energy conservation andcomprehensive u-tilization during 2005 and 2007. In the past few days, 14 departments jointlypublished the Development Program of Energy Conservation and Comprehensive Utilization 2005-2007,(Program for short). They are Standardization Administration of China, National Development andReform Commission, Ministry of Land and Resources, Ministry of Establishment, Ministry ofCommunications, Ministry of Information Industry, Ministry of Waster Resources, Ministry ofAgriculture, Ministry of Commerce, General Administration of Quality Supervision, Inspection andQuarantine of the PRC, State Environmental Protection Administration, State Forestry Bureau, StateOceanic Administration and China Meteorological Bureau.

Comparison of two schemes for district cooling system utilizing cold energy of liquefied natural gas

Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.

Cost Minimization of Wireless Sensor Networks with Unlimited-lifetime Energy for Monitoring Oil Pipelines

Cyber-physical-system (CPS) has been widely used in both civil and military applications. Wireless sensor network (WSN) as the part and parcel of CPS faces energy problem because sensors are battery powered, which results in limited lifetime of the network. To address this energy problem, we take advantage of energy harvesting device (EHD) and study how to indefinitely prolong oil pipeline monitoring network lifetime by reasonable selecting EHD. Firstly, we propose a general strategy worst case-energy balance strategy (WC-EBS), which defines worst case energy consumption (WCEC) as the maximum energy sensor node could expend for oil pipeline monitoring WSN. When the energy collected by EHD is equal or greater than WCEC, network can have an unlimited lifetime. However, energy harvesting rate is proportional to the price of EHD, WC-EBS will cause high network cost. To reduce network cost, we present two optimization strategies, optimization workloadenergy balance strategy (OW-EBS ) and optimization first nodeenergy balance strategy (OF-EBS). The main idea of OW-EBS is to cut down WCEC by reducing critical node transmission workload; OF-EBS confirms critical node by optimizing each sensor node transmission range, then we get the optimal energy harvesting rate in OF-EBS. The experimental results demonstrate that OF-EBS can indefinitely extend network lifetime with lower cost than WC-EBS and OW-EBS, and energy harvesting rate P in each strategy satisfies POF-EBS ≤POW-EBS ≤PWC-EBS. © 2014 Chinese Association of Automation.

Indirect calorimetry to estimate energy requirements for growing and finishing Nellore bulls

Determination of nutritional requirements is the basis for diet formulation. The objectives of this study were to determine the net energy requirements for maintenance （NEro） and weight gain （NEg） in Nellore bulls during the growing and finishing phases, and to estimate efficiency of metabolizable energy （ME） utilization for maintenance and gain （km, kg）. Five Nellore bulls were housed in individual pens at the Universidade Federal de Minas Gerais （Belo Horizonte, Brazil） and evaluated over four experimental periods at 210, 315,378 and 454 kg shrunk body weight （SBW）, approximately. During each period, heat production （HP） was quantified by open circuit indirect calorimetry for three feeding levels： ad libitum, restricted and fasting. The NEm requirement was determined by linear regression between the Log of HP andthe ME intake （MEI） for the ad libitum and restricted levels. This requirement was also determined by quantifying fasting heat production （FHP）. The NEQ requirement was calculated by the difference between MEI and HP during ad libitum feeding. The k and kg were calculated by the relationship between net energy （NE） and ME requirements for maintenance and weight gain （MEm, MEp）, respectively. The NEm requirements per kg of metabolic empty body weight （EBW0.75） fluctuated between 348 and 517 kJ d-1, showing a decreasing trend with age, and were higher than the values reported in the literature. The NEg requirements ranged between 48.3 and 164 kJ kg-1 EBW0.75 d-1, and varied according to age and weight gain. The k values varied between 58.6 and 69.7%, while kg varied between 23.4 and 40.2%. We concluded that NEm and NEg requirements were influenced by age and possibly by the level of stress, nervousness and activity of animals into the respirometry chamber. Further studies should quantify HP with records of positional changes （time spent standing vs. lying down）. Additionally, HP quantification should be repeatedly performed in the same experimental period to obtain a representative value of NEg requirements.

Regional Renewable Energy Optimization Based on Economic Benefits and Carbon Emissions

With increasing renewable energy utilization,the industry needs an accurate tool to select and size renewable energy equipment and evaluate the corresponding renewable energy plans.This study aims to bring new insights into sustainable and energy-efficient urban planning by developing a practical method for optimizing the production of renewable energy and carbon emission in urban areas.First,we provide a detailed formulation to calculate the renewable energy demand based on total energy demand.Second,we construct a dual-objective optimization model that represents the life cycle cost and carbon emission of renewable energy systems,after which we apply the differential evolution algorithmto solve the optimization result.Finally,we conduct a case study in Qingdao,China,to demonstrate the effectiveness of this optimizationmodel.Compared to the baseline design,the proposedmodel reduced annual costs and annual carbon emissions by 14.39%and 72.65%,respectively.These results revealed that dual-objective optimization is an effective method to optimize economic benefits and reduce carbon emissions.Overall,this study will assist energy planners in evaluating the impacts of urban renewable energy projects on the economy and carbon emissions during the planning stage.