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Performance improvement of a pulse tube cryocooler with a single compressor through cascade utilization

Xuming LIU, Xiafan XU, Biao YANG, Xiaotong XI, Liubiao CHEN, Junjie WANG, Yuan ZHOU

《能源前沿（英文）》 2021年 第15卷 第2期   页码 345-357 doi: 10.1007/s11708-020-0708-x

摘要： The high-frequency pulse tube cryocooler (HPTC) has been attracting increasing and widespread attention in the field of cryogenic technology because of its compact structure, low vibration, and reliable operation. The gas-coupled HPTC, driven by a single compressor, is currently the simplest and most compact structure. For HPTCs operating below 20 K, in order to obtain the mW cooling capacity, hundreds or even thousands of watts of electrical power are consumed, where radiation heat leakage accounts for a large proportion of their cooling capacity. In this paper, based on SAGE10, a HPTC heat radiation calculation model was first established to study the effects of radiation heat leakage on apparent performance parameters (such as temperature and cooling capacity), and internal parameters (such as enthalpy flow and gas distribution) of the gas-coupled HPTC. An active thermal insulation method of cascade utilization of the cold energy of the system was proposed for the gas-coupled HPTC. Numerical simulations indicate that the reduction of external radiation heat leakage cannot only directly increase the net cooling power, but also decrease the internal gross losses and increase the mass and acoustic power in the lower-temperature section, which further enhances the refrigeration performance. The numerical calculation results were verified by experiments, and the test results showed that the no-load temperature of the developed cryocooler prototype decreased from 15.1 K to 6.4 K, and the relative Carnot efficiency at 15.5 K increased from 0.029% to 0.996% when substituting the proposed active method for the traditional passive method with multi-layer thermal insulation materials.

关键词： radiation heat leakage     active thermal insulation     cascade utilization     cold energy     performance improvement     cryocooler    

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Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough

Honglun YANG, Qiliang WANG, Jingyu CAO, Gang PEI, Jing LI

《能源前沿（英文）》 2020年 第14卷 第4期   页码 867-881 doi: 10.1007/s11708-020-0707-y

摘要： This paper proposes a comprehensive thermodynamic and economic model to predict and compare the performance of concentrated solar power plants with traditional and novel receivers with different configurations involving operating temperatures and locations. The simulation results reveal that power plants with novel receivers exhibit a superior thermodynamic and economic performance compared with traditional receivers. The annual electricity productions of power plants with novel receivers in Phoenix, Sevilla, and Tuotuohe are 8.5%, 10.5%, and 14.4% higher than those with traditional receivers at the outlet temperature of 550°C. The levelized cost of electricity of power plants with double-selective-coated receivers can be decreased by 6.9%, 8.5%, and 11.6%. In Phoenix, the optimal operating temperature of the power plants is improved from 500°C to 560°C by employing a novel receiver. Furthermore, the sensitivity analysis of the receiver heat loss, solar absorption, and freeze protection temperature is also conducted to analyze the general rule of influence of the receiver performance on power plants performance. Solar absorption has a positive contribution to annual electricity productions, whereas heat loss and freeze protection temperature have a negative effect on electricity outputs. The results indicate that the novel receiver coupled with low melting temperature molten salt is the best configuration for improving the overall performance of the power plants.

关键词： concentrated solar power     parabolic trough receiver     heat loss     solar energy     annual performance    

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Robust switched fractional controller for performance improvement of single phase active power filter

H. AFGHOUL,F. KRIM,D. CHIKOUCHE,A. BEDDAR

《能源前沿（英文）》 2016年 第10卷 第2期   页码 203-212 doi: 10.1007/s11708-015-0381-7

摘要： A novel controller is proposed to regulate the DC-link voltage of a single phase active power filter (SPAPF). The proposed switched fractional controller (SFC) consists of a conventional PI controller, a fractional order PI (FO-PI) controller and a decision maker that switches between them. Commonly, the conventional PI controller is used in regulation loops due to its advantages in steady-state but it is limited in transient state. On the other hand, the FO-PI controller overcomes these drawbacks but it causes dramatic degradation in control performances in steady-state because of the fractional calculus theory and the approximation method used to implement this kind of controller. Thus, the purpose of this paper is to switch to the PI controller in steady-state to obtain the best power quality and to switch to the FO-PI controller when external disturbances are detected to guarantee a fast transient state. To investigate the efficiency and accuracy of the SFC considering all robustness tests, an experimental setup has been established. The results of the SFC fulfill the requirements, confirm its high performances in steady and transient states and demonstrate its feasibility and effectiveness. The experiment results have satisfied the limit specified by the IEEE harmonic standard 519.

关键词： conventional PI controller     fractional calculus (FC)     total harmonic distortion (THD)     Oustaloup continuous approximation (OCA)     single phase active power filter (SPAPF)    

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Liquid metal cooling in thermal management of computer chips

MA Kunquan, LIU Jing

《能源前沿（英文）》 2007年 第1卷 第4期   页码 384-402 doi: 10.1007/s11708-007-0057-3

摘要： With the rapid improvement of computer performance, tremendous heat generation in the chip becomes a major serious concern for thermal management. Meanwhile, CPU chips are becoming smaller and smaller with almost no room for the he

关键词： tremendous     computer performance     generation     management     improvement    

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Requirements in performance measurement systems of construction projects from the lean production perspective

Karina B. BARTH, Carlos T. FORMOSO

《工程管理前沿（英文）》 2021年 第8卷 第3期   页码 442-455 doi: 10.1007/s42524-020-0108-2

摘要： Performance measurement (PM) generates useful data for process control, facilitates communication between different sectors, and helps to align efforts on the most important aspects of the business. Thus, PM plays a key role in the management of projects and organizations. PM is also important in the implementation of lean production principles and methods, such as reducing the share of nonvalue-adding activities, increasing process transparency, building continuous improvement into the process, and benchmarking. Moreover, the adoption of the lean production philosophy requires changes in PM. Despite its importance, limited studies have been conducted on the use of PM systems for assessing the impact of lean production programs in construction projects. In addition, studies on how lean companies (or projects) use performance measurement and to what extent the indicators adopted reflect the result of actions that have been undertaken are limited. This study proposes a set of requirements in PM systems of construction projects from the perspective of lean production and a taxonomy of performance metrics for lean production systems. Five empirical studies have been carried out on construction companies from South America involved in the implementation of lean production systems. The scope of this investigation is limited to the construction projects as production systems rather than PM at the level of construction organizations.

关键词： performance measurement     lean construction     production management     continuous improvement     metrics    

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Improvement of engine performance with high compression ratio based on knock suppression using Miller

Haiqiao WEI, Jie YU, Lei ZHOU

《能源前沿（英文）》 2019年 第13卷 第4期   页码 691-706 doi: 10.1007/s11708-019-0621-3

摘要： In theory, high compression ratio has the potential to improve the thermal efficiency and promote the power output of the SI engine. However, the application of high compression ratio is substantially limited by the knock in practical working process. The objective of this work is to comprehensively investigate the application of high compression ratio on a gasoline engine based on the Miller cycle with boost pressure and split injection. In this work, the specific optimum strategies for CR10 and CR12 were experimentally investigated respectively on a single cylinder DISI engine. It was found that a high level of Miller cycle with a higher boost pressure could be used in CR12 to achieve an effective compression ratio similar to CR10, which could eliminate the knock limits at a high compression ratio and high load. To verify the advantages of the high compression ratio, the fuel economy and power performance of CR10 and CR12 were compared at full and partial loads. The result revealed that, compared with CR10, a similar power performance and a reduced fuel consumption of CR12 at full load could be achieved by using the strong Miller cycle and split injection. At partial load, the conditions of CR12 had very superior fuel economy and power performance compared to those of CR10.

关键词： high compression ratio     knock     Miller cycle     split injection     engine performance    

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Improvement potential of today’s WEEE recycling performance: The case of LCD TVs in Belgium

Paul Vanegas, Jef R. Peeters, Dirk Cattrysse, Wim Dewulf, Joost R. Duflou

《环境科学与工程前沿（英文）》 2017年 第11卷 第5期 doi: 10.1007/s11783-017-1000-0

摘要： Waste of electrical and electronic equipment (WEEE) constitutes one of the most relevant waste streams because of the quantity and presence of valuable materials. However, there is limited knowledge on the resource potential of urban mining WEEE, as data on material composition, and the efficiency of current recycling treatments are still scarce. In this article, an evaluation of the recycling performance at a national level for one of the fastest growing e-waste streams: LCD TVs is carried out through the following four steps. Firstly, material characterisation is performed by means of sampling of the waste stream. Secondly, a material flow analysis is conducted by evaluating the separation performance of a recycling plant in Belgium. Thirdly, the recovered economic value and avoided environmental impact (EI) of the analysed recycling system is assessed. Finally, the potential of urban mining for Belgium is forecasted. The analysis shows that while recycling performance for ferrous metals and aluminium are relatively high; there is substantial room to better close the material loops for precious metals (PM) and plastics. PMs and plastics account for 66 % of the economic value in LCD TVs and 57% of the EI. With the current, commonly applied recycling technology only one-third of the PM and housing plastics are recycled; meaning that for these materials, at a national level for Belgium, there is a potential for improvement that represents 3.3 million euros in 2016 and 6.8 million euros in 2025.

关键词： Recycling     Waste of electrical and electronic equipment (WEEE)     Material flow analysis     LCD TVs     Precious metals     Plastics    

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Exploring differentiated improvement strategies of cultivated land quality in China

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023523

摘要：

● Cultivated land quality can be considered in four dimensions: suitability, contiguity, resistance, and ecological stress.

关键词： China     cultivated land quality     differentiated improvement     food security    

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Improvement of part-load performance of gas turbine by adjusting compressor inlet air temperature and

《能源前沿（英文）》 2022年 第16卷 第6期   页码 1000-1016 doi: 10.1007/s11708-021-0746-z

摘要： A novel adjusting method for improving gas turbine (GT) efficiency and surge margin (SM) under part-load conditions is proposed. This method adopts the inlet air heating technology, which uses the waste heat of low-grade heat source and the inlet guide vane (IGV) opening adjustment. Moreover, the regulation rules of the compressor inlet air temperature and the IGV opening are studied comprehensively to optimize GT performance. A model and calculation method for an equilibrium running line is adopted based on the characteristic curves of the compressor and turbine. The equilibrium running lines calculated through the calculation method involve three part-load conditions and three IGV openings with different inlet air temperatures. The results show that there is an optimal matching relationship between IGV opening and inlet air temperature. For the best GT performance of a given load, the IGV could be adjusted according to inlet air temperature. In addition, inlet air heating has a considerable potential for the improvement of part-load performance of GT due to the increase in compressor efficiency, combustion efficiency, and turbine efficiency as well as turbine inlet temperature, when inlet air temperature is lower than the optimal value with different IGV openings. Further, when the IGV is in a full opening state and an optimal inlet air temperature is achieved by using the inlet air heating technology, GT efficiency and SM can be obviously higher than other IGV openings. The IGV can be left unadjusted, even when the load is as low as 50%. These findings indicate that inlet air heating has a great potential to replace the IGV to regulate load because GT efficiency and SM can be remarkably improved, which is different from the traditional viewpoints.

关键词： inlet air temperature     inlet guide vane (IGV) opening     part-load     equilibrium running line     gas turbine (GT) efficiency     surge margin (SM)    

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钢铁结构材料的高性能化

翁宇庆

《中国工程科学》 2002年 第4卷 第3期   页码 48-53

摘要：

叙述了以细化钢铁结构材料的晶粒尺寸为核心，将现有钢材强度和寿命翻番的基本进展；在保持塑性提高和价格下降的同时，碳素结构钢板带材屈服强度从235 MPa已提高到420～470 MPa，塑性由最大26%提高到29%～34%；建筑螺纹钢由一级提高到三级，碳—锰钢由二级提高到四级，且抗地震性能好；高强抗延迟断裂螺栓钢，已达到世界最高的13.9级。

关键词： 钢铁材料     基础研究     高性能化     进展    

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Research progress on genetic improvement of

Chuanping YANG

《农业科学与工程前沿（英文）》 2017年 第4卷 第4期   页码 391-401 doi: 10.15302/J-FASE-2017183

摘要： Suk. is one of the most widely distributed species of , the fourth most valuable timber species in north-eastern China and also a common tree species for landscaping. Over the past 30 years, effective progress has been made in genetic improvement and molecular breeding of . There has been extensive research on breeding techniques, including the collection and conservation of germplasm resources, provenance trials, intensive breeding techniques, crossbreeding and asexual propagation techniques, ploidy breeding and mutation breeding technology, genome sequencing, gene cloning, transgenic and molecular mechanisms of wood formation. A germplasm resource collection has been established by collecting different provenances, and full-sib and half-sib families. In addition, the geographic variation patterns of provenances have been revealed, and the provenance division and superior provenance selections made. flowering and seeding have been improved through intensive breeding techniques. Interspecific hybridization, intraspecific hybridization and parallel crosses were made using fine parents, and intensive seed orchards have been established. Systems of asexual propagation, including cuttings, grafting and tissue culture have been established. A tetraploid was successfully constructed and a triploid seed orchard established. The growth, wood property and resistance genes of have been cloned. An efficient transgenic system mediated by was established, and genes encoding insect resistance, drought resistance and salt tolerance, lignin synthesis, flowering, hormone transport and balance obtained. molecular markers were developed and the high density genetic map constructed. All this research has provided a model and data for the foundation of forest genetic improvement and applied research.

关键词： Betula platyphylla     genetic improvement     molecular breeding     seed orchard    

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A review of systematic evaluation and improvement in the big data environment

Feng YANG, Manman WANG

《工程管理前沿（英文）》 2020年 第7卷 第1期   页码 27-46 doi: 10.1007/s42524-020-0092-6

摘要： The era of big data brings unprecedented opportunities and challenges to management research. As one of the important functions of management decision-making, evaluation has been given more functions and application space. Exploring the applicable evaluation methods in the big data environment has become an important subject of research. The purpose of this paper is to provide an overview and discussion of systematic evaluation and improvement in the big data environment. We first review the evaluation methods based on the main analytic techniques of big data such as data mining, statistical methods, optimization and simulation, and deep learning. Focused on the characteristics of big data (association feature, data loss, data noise, and visualization), the relevant evaluation methods are given. Furthermore, we explore the systematic improvement studies and application fields. Finally, we analyze the new application areas of evaluation methods and give the future directions of evaluation method research in a big data environment from six aspects. We hope our research could provide meaningful insights for subsequent research.

关键词： big data     evaluation methods     systematic improvement     big data analytic techniques     data mining    

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项目业绩系统评价模型及其改良研究

利镇有,何继善

《中国工程科学》 2011年 第13卷 第8期   页码 10-14

摘要：

项目系统评价实际上是项目驱动型公司业绩和效率持续提高的重要而必要的手段。通过排除一些评估过程中易于产生歧义的复杂方法和手段，对国际项目管理协会（IPMA）所广泛采用的项目卓越模型（project excellence model, PE模型）进行改良，提出更为合理和透明简约的模型和手段，对项目进行全面而系统的评价，更好地评价项目管理过程、业绩和项目利益相关方的得失。改良后的模型与原模型所提出的评价准则更为一致，更易于进行项目评价的操作与项目驱动型公司的项目知识管理。

关键词： 项目评价     项目管理     项目卓越模型     项目知识管理    

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Quality and efficiency improvement technology for five megawatt offshore wind turbines and its application

Huali HAN

《工程管理前沿（英文）》 2020年 第7卷 第4期   页码 618-621 doi: 10.1007/s42524-020-0142-0

关键词： renewable energy     megawatt offshore wind turbine     technology-driven     quality improvement    

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Embryo-mediated genome editing for accelerated genetic improvement of livestock

Zachariah MCLEAN, Björn OBACK, Götz LAIBLE

《农业科学与工程前沿（英文）》 2020年 第7卷 第2期   页码 148-160 doi: 10.15302/J-FASE-2019305

摘要：

Selecting beneficial DNA variants is the main goal of animal breeding. However, this process is inherently inefficient because each animal only carries a fraction of all desirable variants. Genome editing technology with its ability to directly introduce beneficial sequence variants offers new opportunities to modernize animal breeding by overcoming this biological limitation and accelerating genetic gains. To realize rapid genetic gain, precise edits need to be introduced into genomically-selected embryos, which minimizes the genetic lag. However, embryo-mediated precision editing by homology-directed repair (HDR) mechanisms is currently an inefficient process that often produces mosaic embryos and greatly limits the numbers of available edited embryos. This review provides a summary of genome editing in bovine embryos and proposes an embryo-mediated accelerated breeding scheme that overcomes the present efficiency limitations of HDR editing in bovine embryos. It integrates embryo-based genomic selection with precise multi-editing and uses embryonic cloning with elite edited blastomeres or embryonic pluripotent stem cells to resolve mosaicism, enable multiplex editing and multiply rare elite genotypes. Such a breeding strategy would enable a more targeted, accelerated approach for livestock improvement that allows stacking of beneficial variants, even including novel traits from outside the breeding population, in the most recent elite genetic background, essentially within a single generation.

关键词： animal breeding     cattle     cloning     CRISPR/Cas9     cytoplasmic injection     embryo     genome editing     germline chimaeras     HDR     livestock improvement     TALENs    

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标题 作者 时间 类型 操作

Performance improvement of a pulse tube cryocooler with a single compressor through cascade utilization

Xuming LIU, Xiafan XU, Biao YANG, Xiaotong XI, Liubiao CHEN, Junjie WANG, Yuan ZHOU

期刊论文

Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough

Honglun YANG, Qiliang WANG, Jingyu CAO, Gang PEI, Jing LI

期刊论文

Robust switched fractional controller for performance improvement of single phase active power filter

H. AFGHOUL,F. KRIM,D. CHIKOUCHE,A. BEDDAR

期刊论文

Liquid metal cooling in thermal management of computer chips

MA Kunquan, LIU Jing

期刊论文

Requirements in performance measurement systems of construction projects from the lean production perspective

Karina B. BARTH, Carlos T. FORMOSO

期刊论文

Improvement of engine performance with high compression ratio based on knock suppression using Miller

Haiqiao WEI, Jie YU, Lei ZHOU

期刊论文

Improvement potential of today’s WEEE recycling performance: The case of LCD TVs in Belgium

Paul Vanegas, Jef R. Peeters, Dirk Cattrysse, Wim Dewulf, Joost R. Duflou

期刊论文

Exploring differentiated improvement strategies of cultivated land quality in China

期刊论文

Improvement of part-load performance of gas turbine by adjusting compressor inlet air temperature and

期刊论文

钢铁结构材料的高性能化

翁宇庆

期刊论文

Research progress on genetic improvement of

Chuanping YANG

期刊论文

A review of systematic evaluation and improvement in the big data environment

Feng YANG, Manman WANG

期刊论文

项目业绩系统评价模型及其改良研究

利镇有,何继善

期刊论文

Quality and efficiency improvement technology for five megawatt offshore wind turbines and its application

Huali HAN

期刊论文

Embryo-mediated genome editing for accelerated genetic improvement of livestock

Zachariah MCLEAN, Björn OBACK, Götz LAIBLE

期刊论文