基于动态负荷的区域冷热电联供系统冷价制定

针对某区域冷热电联供系统(简称区域联供系统),基于动态负荷预测,建立以冷量损失计算模型、区域联供系统自用电计算模型为核心的冷价计算模型,分析了冷价的敏感性影响因素。

中央空调系统能量包计费方式研究

采用能量计费方式虽不能直接减少能源消耗,但是可以改变用户用能习惯。本文提出中央空调系统能量包计费方式,基于冷负荷来设定基础能量包,在基础能量包范围内的单位冷价低,超出基础能量包范围内,提高单位冷价,以达到节能减排的目的。

Analysis and Evaluation Indicator Selection of Chilling Tolerance of Different Cotton Genotypes

[Objectivc] This study aimed to investigate the chilling tolerance of seedlings of different cotton genotypes and screen appropriate indicators for assess- ing chilling tolerance, to establish reliable mathematical evaluation model for chilling tolerance of cotton, thus providing theoretical basis for breeding and promoting new chilling-tolerant cotton germplasms and large-scale evaluation of chilling tolerance of cotton varieties. [Method] Fifteen cotton varieties （lines） were used as experimental materials. The photosynthetic gas exchange parameters, chlorophyll fluorescence ki- netic parameters, chlorophyll content, relative soluble sugar content, malonaldehyde content, relative proiine content, relative conductivity and other 12 physiological indi- cators of seedling leaves under low temperature treatment （5 ℃, 12 h） and recovery treatment （25 ℃. 24 h） were determined; based on the chilling tolerance coefficient （CTC） of various individual indicators, the comprehensive evaluation of chilling toler- ance was conducled by using principal component analysis, hierarchical cluster anal- ysis and stepwise regression analysis. [Result] The results showed that the 12 indi- vidual physiological indicators could be classified into 7 independent comprehensive components by principal component analysis; 15 cotton varieties （lines） were clus- tered into three categories by using membership function method and hierarchical cluster analysis; the mathematical model for evaluating chilling tolerance of cotton seedlings was established： D =0.275 -0.244Fo1 ＋0.206Fv/Fm1＋0.326g,%-0.056SS ＋ 0.225MDA＋O.O38REC （FF=0.995）, and the evaluation accuracy of the equation was higher than 94.25%,0. Six identification indicators closely related to chilling tolerance were screened, including Fo,, Fv/Fm1, Seedling leaves of cotton varieties （lines） gs2, SS, MDA, and REC. [Conclusion] with high chilling tolerance are less dam- aged under low temperature stress, and are able to maintain relatively high photo- synthetic electron transport capacity and high stomatal conductance after recovery treatment, which is contributed to gas exchange and recovery of photosynthetic ca- pacity. Determination of the six indicators under the same stress condition can be adopted for rapid identification and prediction of the chilling tolerance of other cotton varieties, which provides basis for the breeding, promotion, identification and screen- ing of chilling tolerant germplasms.

Effect of cerium ion(Ⅲ) on corrosion resistance of organic-inorganic hybrid coating on surface of aluminum-tube used in refrigeration equipment

Organic?inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol?gel method, and the structure of the coating was confirmed by FT-IR. The results of the characterization show that the corrosion resistance of the coating with 1.5 mmol/L cerium ion (III) gains significant improvement, in which the colour retention time of CuSO4 extends to 500 s, the anti-acid and alkali corrosion rates reduce by 67% and 70% compared with the blank one, respectively, and the salt spray tests also show good corrosion resistance. The electrochemical tests demonstrate that the self-corrosion current density and potential of the sample with hybrid coating are about 2.877×10?7 A/cm2 and?0.550 V, respectively. The metallographic and SEM images show that the hybrid coating is uniform and dense, and the EDS analysis confirms that the coating is mainly composed of Al, Si and Ce elements.

Research and application of methods for effectiveness evaluation of mine cooling system

Regarding the complexity and inconsistency of results in existing evaluation methods of mine cooling system, this paper clarifies the advantages, disadvantages and application of various mine cooling sys- tems through principle analysis, and divides all the cooling systems into air-cooling, ice-cooling and water-cooling according to the transportation of cold energy. On this basis, the paper proposes a simple and efficient evaluation method for mine cooling system. The first index of this method is the air temper- ature at point C which is 15 m away from the return wind corner at working face. A cooling system will be judged ineligible if the air temperature at point C is above 30 ℃ during operation, because in this case, the combustible gases in coal will sharply overflow, inducing gas incidents. Based on the preliminary judg- ment of the first index, another two evaluation indexes are proposed based on the cooling ability and dehumidification of an airflow volume of 1000 m3/min at point C to evaluate the investment and opera- tion cost of mine cooling system. This evaluation method has already been successfully applied in the cooling system design of Zhangshuanglou coal mine.

Multi-objective optimization of rolling schedule based on cost function for tandem cold mill

In terms of tandem cold mill productivity and product quality, a multi-objective optimization model of rolling schedule based on cost fimction was proposed to determine the stand reductions, inter-stand tensions and rolling speeds for a specified product. The proposed schedule optimization model consists of several single cost fi.mctions, which take rolling force, motor power, inter-stand tension and stand reduction into consideration. The cost function, which can evaluate how far the rolling parameters are from the ideal values, was minimized using the Nelder-Mead simplex method. The proposed rolling schedule optimization method has been applied successfully to the 5-stand tandem cold mill in Tangsteel, and the results from a case study show that the proposed method is superior to those based on empirical formulae.

The First Natural Ventilation Assessment in Building Design in Djibouti

With a sustained period of economic growth, rapidly growing populations and with more diversified economies Africa need sustainable development; hence the greater need for massive investments in energy. Sub-Saharan countries such as Djibouti have the potential and ability to harness their natural ventilation as a passive cooling system for designing new houses. The rapid expansion of the Djibouti city is affecting negatively the environment and the safety and comfort of its inhabitants. Proper atmospheric urban planning and management are key to making cities environmentally friendly and sustainable. Based on energy consumption, climate conditions in Djibouti and numerical analysis using Computational Fluid Dynamics （CFD）, it is apparent that the natural ventilation creates a thermally comfortable indoor environment in buildings during the cool season of the year. Measured wind data from two measurement systems are presented and discussed. Statistical analyses, wind rose, Weibull distribution were carried out to understand the natural ventilation characteristic, which is used for evolving the basic criteria for economic viability of building in the semi-arid climate of Djibouti. The study found that it is possible to benefit from natural ventilation in buildings during the cool season of the year.

Thermocline Thickness Evaluation on Stratified Thermal Energy Storage Tank of Co-generated District Cooling Plant

Temperature distribution of water inside of thermal storage tank reflects the condition of cooling energy stored in the tank. It can be used to define important parameters required for evaluation the performance of thermal storage tank. In this study, the thermocline thickness was evaluated for two cases of charging cycles： case Ⅰ at 393 m^3 / hr and case Ⅰ at 524 m^3 / hr. Hourly data were used for the study. Curve fitting approach was used to plot the temperature distribution profiles. Results obtained revealed that the fitting function enabled quantification of thermocline thickness of the thermal storage tank. The parameters that were determined are average cool-warm water temperatures and cool water depth in the tank. The approach offer an advantage to determine the thermocline thickness based on functionally relationship of temperature distribution profile. Results obtained shown that thermocline thickness increases at the higher flow rate. This was due to increased mixing of cool and warm water. It was also noted that thicker thermocline occurred in the region nearby the inlet diffuser. The findings indicate that the operating thermal energy storage as performing as a stratified tank.

＂Jerusalem＂ of China： The Neoteric Christian Churches in Shaanxi before 1949

Christian buildings in Shaanxi already have more than 1,300 years development history since the first church was built in Chang＇an in 635 AD. The Rapid development of Christian buildings started from 1840 due to the entry of foreign missionaries. Various types of Christian buildings rose up in the province, were constructed by local builder, but designed and funded by foreign missionaries. In comparison to other Christian buildings, churches have unique historical value, cultural value and also special meaning in architecture art. However, their cultural heritage value has not yet been sufficiently considered. They are facing the prospect of being damaged and demolished, even in nowadays. It is incumbent that their architecture to be historically evaluated and that ways to be found to preserve them. In this paper, the author will focus on the neoteric Christian churches and illustrate the architecture by taking examples from the churches in Shaanxi, along with the intention to clarify the relationship between social background and the history of evolution of these churches. In addition, the authors have taken the chance to understand more comprehensively about the fascinating history of these Christian churches by way of field surveys and taping into archival documents.

Economical Evaluation of a Low-Enthalpy Geothermal Resource Located in an Arid-Zone Area

In this work an economical evaluation that established the viability of a low enthalpy geothermal resource as an energy source in north Africa is presented. The factors considered included the payback period, average rate of return, net present value, and net benefit-cost ratio. The model was based on utilising the energy source to energise four models that comprised thermal equipment consisting of water/air cooled single/half effect lithium bromide water mixture absorption chillers and an R-245fa organic Rankine cycle. These modelled cycles were based on the energy demand for Waddan city a community in southern Libya which has a demand for combined cooling/electricity only or cooling/electricity with district hot water supply. The results revealed that all of the proposed simulated stand-alone models, except the water-cooled half effect chiller, are not economically viable unless they are heavily subsidized or combined with the district hot water supply at least in the winter season.

A Study on the Evaluation of Heating and Cooling Energy Efficiency in Residential Buildings for Climatic Zones of Turkey

In Turkey, most of the common type projects of mass production residential buildings are being developed and constructed by TOK1 （Housing Development Administration of Turkey）. These buildings, in which energy efficient approach has been disregarded for years, cause to gradually increase on heating and cooling energy consumptions. In regards to national economics, it is essential to evaluate energy efficiency and to develop suggestions to decrease energy consumptions in residential buildings. To achieve appropriate solutions, cost evaluation also becomes necessary. Therefore, this paper aims to introduce a study which serves the purpose of producing a choice of energy efficient solutions in order to reduce energy consumptions and energy cost. In this study, different heating and cooling energy efficient scenarios have been developed for a selected residential building, constructed by TOKI, for climatic zones of Turkey. For each scenario, energy simulations have been executed by means of the simulation program--DesignBuilder, the user-friendly visual interface of EnergyPlus, and cost analysis has been carried out by using the net present value and discounted payback period method. As a result, energy and cost effective solutions have been presented and discussed for different climatic zones.

分布式供能系统经济收益分析中冷热价的确定

分布式供能系统的经济收益包括冷、热、电,提出采用两种定价方法确定冷价、热价。结合工程实例,对这两种定价方法进行了比较。

Performance Research of a Micro-CCHP System with Adsorption Chiller

This paper describes a new micro-combined cooling, heating and power （CCHP） system, which is especially suitable for domestic and light commercial applications. It mainly consists of a natural gas-fired internal combustion engine, a silica gel-water adsorption chiller and other heat recovery units. In order to study the energy efficiency and economic feasibility, an experimental investigation has been carried out. The experimental system has a rated electricity power of 12 kW, a rated cooling capacity of 9 kW and a rated heating capacity of 28 kW. Evaluation and analysis of the system are discussed in detail. The testing results show that the energy efficiency of the overall system depends on different modes. The overall thermal and electrical efficiency is over 70%. Higher heat load supplied causes higher efficiency of the system. Economic evaluation shows that the micro-CCHP system enjoys a small capital cost and short payback period, which is easily accepted by customers. At current natural gas price of 1.9 RMB/m^3 （nominal condition） and electric price of 0.754 RMB/（kW.h）, the total capital cost is only 90 000 RMB with a payback period of 3.21 years.