压缩空气储能系统性能分析研究

压缩空气储能系统是一种新型大规模电力储能系统,目前已发展到第三代,系统效率是评价系统性能的重要指标,已有的研究很少基于相同的系统配置定量研究三代系统效率的差异。本文基于相同的系统配置,针对三代典型系统分别建模,比较各系统能量转换效率,分析能量损失分布,同时研究压缩机压比对系统效率的影响。仿真结果表明,先进绝热压缩空气储能系统回收利用压缩热,效率分别为63.17%(储热介质为导热油)和58. 71%(储热介质为水),高于传统系统(44.95%)和带回热的系统(49.04%)。提高压缩机压比,对各系统的能量效率影响不同。本文仿真研究结果为提高对三代储能系统的热力性能认识提供了理论支撑。

Selection of Heat Recovery Ventilators in Different Climate Zones of China

Considering four different climate zones in China, an investigation on the choice of heat recovery ventilator for the buildings with little moisture emissions is carried out. The annual composition of energy consumption of air intake for per unitary air ventilation flow rate is evaluated by employing the testing data of climatic parameters in eight selected cities. The analysis shows that the total heat recovery is suitable in a controlled ventilation system with air humidity controlled during heating period of all the climates. For the building without air humidity controlled in winter, the sensible heat recovery ventilators can be used in severe cold and cold regions, and total heat recovery systems are more suitable for energy saving in hot summer and cold winter and hot summer and warm winter regions.

Numerical Simulation of Flameless Premixed Combustion with an Annular Nozzle in a Recuperative Furnace

This paper reports an investigation of Computational Fluid Dynamics(CFD)on the influence of injection momentum rate of premixed air and fuel on the flameless Moderate or Intense Low oxygen Dilution(MILD) combustion in a recuperative furnace.Details of the furnace flow velocity,temperature,O2,CO2 and NOx concentrations are provided.Results obtained suggest that the flue gas recirculation plays a vital role in establishing the premixed MILD combustion.It is also revealed that there is a critical momentum rate of the fuel-air mixture below which MILD combustion does not occur.Moreover,the momentum rate appears to have less significant influence on conventional global combustion than on MILD combustion.

INTRASEASONAL OSCILLATIONS IN ASIA TO WESTERN PACIFIC REGION IN BOREAL SUMMER:CONTRASTIVE ANALYSIS FOR ACTIVE AND INACTIVE YEARS OF TROPICAL CYCLONES

Comparative analysis is carried out by using finite-domain power spectrum and lagged regression methods for the propagating characteristics and air-sea interaction processes of intraseasonal oscillations (ISOs) in the Asia to western Pacific (AWP) region during the boreal summer between the active and inactive tropical cyclone (TC) years from 1979 to 2004.The results show as follows.(1) There exist more significant eastward propagating characteristics of the ISO in the active TC years over the whole AWP region.The ISOs of convection propagate zonally with more eastward extension in the years with active tropical cyclone activities,during which the 20-60-day period is strengthened,western Pacific becomes an area with evident characteristics of the propagation that is closely related to TC activities.(2) The air-sea interaction processes are the same in both active and inactive TC years,and the energy exchanges between the air and the sea play a role in maintaining the northwestward propagation of ISOs.(3) The air-sea interaction is more intensive in the active TC years than in the inactive ones.It is particularly true for the latent heat release by condensation as the result of convection,which may be one of the reasons resulting in significant differences in characteristics of ISOs between the active and inactive TC years.

Analysis on Cost and Profit in Farming Activity in Malaysia

There is an excessive dissimilarity between scholars in how to accumulate output costs. Worldwide farming advancement is concerned with yield enhancement instead of a holistic natural source management for food safety. Nevertheless, knowledge regarding the achievement of agriculture systems subject to natural and conventional management in tropical and subtropical areas is insufficient. Why do several farmers record less profit than other farmers？ Cost in agriculture activity influences the volume of profit gained by farmers. The number of respondents was 53. Data analysis was made using linear regression analysis to achieve the objective. The scatter diagram manifested a positive connection in cost and profit in agriculture activity from 2009 to 2013. For each cost increase in 2009-2012, the model forecasts a rise of returns for every year. The rate of profit earned by farmers every year shifts considerably in relation to the rate of cost in agriculture activity. This study recommends common accounting principles practices that exercise bookkeeping and managerial accounting to enhance farmstead management and profit. Future research may be conducted on the use of compost fertilizer in increasing agricultural income.

Variability features of the width of the tropical belt from COSMIC radio occultation data

In this work, we analyzed time-series and trends of the tropical belt edges and widths with three methods based on the tropopause using new global positioning system radio occultation(GPS RO) data from the Constellation Observing System for Meteorology, Ionosphere, and Climate(COSMIC) mission for September 2006–February 2014. The results from the three methods agreed well with previous studies and new features were found. To avoid the El Ni?o Southern Oscillation(ENSO) and Quasi-Biennial Oscillation(QBO) influence, we applied a simple multiple linear regression model to the monthly anomalies to obtain the tropical belt edges and width trends. During the study, we found equatorward movements of the tropical belt edges on both hemispheres. The narrowing of the tropical belt mainly occurred in the Pacific Ocean. We also found that the deseasonalized monthly anomalies of the tropical belt width were closely related with the ENSO and QBO. The tropical belt at a height of 15 km was mostly closely related with the ENSO. The correlations between the QBO and the tropical belt were consistent for the three methods.