Integration of wind turbine with heliostat based CSP/CPVT system for hydrogen production and polygeneration: A thermodynamic comparison

In this study, two wind-solar-based polygeneration systems namely CES-1 and CES-2 are developed, modeled, and analyzed thermodynamically. CES-1 hybridizes a heliostat based CSP system with wind turbines while CES-2 integrates heliostat-based CPVT with wind turbines. This study aims to compare the production and thermodynamics performance of two heliostat based concentrated solar power technologies when hybridized with wind turbines. The systems have been modeled to produce, freshwater, hot water, electricity, hydrogen, and cooling with different cycles/subsystems. While the overall objective of the study is to model two polygeneration systems with improved energy and exergy performances, the performances of two solar technologies are compared. The wind turbine system integrated with the comprehensive energy systems will produce 1.14 MW of electricity and it has 72.2% energy and exergy efficiency. Also, based on the same solar energy input, the performance of the heliostat integrated CPVT system (CES-2) is found to be better than that of the CSP based system (CES-1). The polygeneration thermal and exergy efficiencies for the two systems respectively are 48.08% and 31.67% for CES-1; 59.7% and 43.91% for CES-2. Also, the electric power produced by CES-2 is 280 kW higher in comparison to CES-1.     

Recent Developments in Integrated Solar Combined Cycle Power Plants

Global concern for depleting fossil fuel reserves have been compelling for evolving power generation options using renewable energy sources. The solar energy happens to be a potential source for running the power plants among renewable energy sources. Integrated Solar Combined Cycle(ISCC) power plants have gained popularity among the thermal power plants. Traditional ISCC power plants use Direct Steam Generation(DSG) approach. However, with the DSG method, the ISCC plant’s overall thermal efficiency does not increase significantly due to variations in the availability of solar energy. Thermal Energy Storage(TES) systems when integrated into the solar cycle can address such issues related to energy efficiency, process flexibility, reducing intermittency during non-solar hours. This review work focuses and discusses the developments in various components of the ISCC system including its major cycles and related parameters. The main focus is on CSP technologies, Heat Transfer Fluid(HTF), and Phase Change Material(PCM) used for thermal energy storage. Further, study includes heat enhancement methods with HTF and latent heat storage system. This study will be beneficial to the power plant professionals intending to modify the solar-based Combined Cycle Power Plant(CCPP) and to retrofit the existing Natural Gas Combined Cycle(NGCC) plant with the advanced solar cycle.     

Multi-class grasping classifiers using EEG data and a common spatial pattern filter

This paper describes the classification of various human actions from brain activity. In particular, we focus on grasping movements and estimate grasping patterns from electroencephalogram (EEG) data. EEG data is converted to grasping features by using a common spatial pattern filter (CSP filter), and the features are subsequently classified into grasping categories by using the k-nearest neighbor method. We tested the pipeline of feature extraction and classification on the EEG dataset. The EEG data were acquired while participants grasped an object according to the Cutkosky’s grasping taxonomy, in which grasping movements are categorized into nine power-type grasping patterns and seven precision-type grasping patterns. The best classification rate for 9-class power-type grasping patterns was 48% and for 7-class precision-type grasping patterns was 40%.     

Formalization and analysis of the REST architecture from the process algebra perspective

As one of the most promising architectural styles, REpresentational State Transfer (REST) was proposed to support a scalable and reliable design for large-scale distributed hypermedia systems such as the World Wide Web (WWW). However, the rapid development of RESTful systems brings the misunderstanding and misapplying of the REST architecture. As a consequence, considerable confusions about REST exist and many examples of supposedly RESTful applications violate key REST constraints. Thus, it is of significant importance to give a better and explicit understanding of REST architecture to guide the design and implementations of RESTful systems.In this paper, we give a formalization and analysis of the REST architecture from the perspective of Communicating Sequential Processes (CSP), which is one of the most famous process algebras. In particular, we present a formal model to capture essential features for the REST architecture, where components (together with one connector) of RESTful systems are modeled as CSP processes. Besides, resources are also abstracted as CSP processes. Furthermore, all the REST constraints, including Client–Server, Cacheable, Stateless, Uniform Interface, Layered and Code-On-Demand, are described in our framework and implemented in the model checker Process Analysis Toolkit (PAT) to check whether a system breaks REST constraints or not. It is difficult to ensure that a system is RESTful system, because many unRESTful systems may also contain unRESTful properties besides satisfying the six REST constraints. Thus, a complementary approach is proposed in this paper to check the system from a different perspective; that is, if a system breaks any specification of the REST constraints, then it is not a RESTful system. Finally, to show the feasibility of our approach, we illustrate a case study about an application scenario for environment monitoring. One feature of the proposed framework for the REST architecture is that it not only confines to HyperText Transport Protocol (HTTP) but can also be applied to other REST-compliant protocols, e.g., Constrained Application Protocol (CoAP). Consequently, through the general framework, a better understanding of the REST architecture can be achieved, and moreover, implementations and designs of RESTful systems can benefit from it.     

包钢CSP热轧卷板纵裂缺陷分析与控制

为了研究薄板厂CSP产线热轧卷板纵裂缺陷产生原因,对连铸工艺及设备各运行参数进行了调查分析。结果表明,连铸机振动台振动精度差、结晶器铜板结垢是导致热轧卷纵裂缺陷的主要原因。采取调整振动参数、提升振动台对中精度以及控制铜板结垢等措施后,热轧卷板表面纵裂纹缺陷显著降低,纵裂率由最高的1.15%降至0.10%以下。针对CSP铸机,在保证结晶器铜板导热良好的前提下,需严格控制结晶器振动台四连杆机构的关节轴承间隙在0.02 mm以内,振动台台面标高偏差在0.05 mm之内。结晶器振动在水平方向的位移量在0.1 mm以内为宜。     

Hydrogen production by coupling pressurized high temperature electrolyser with solar tower technology

Solar hydrogen production by coupling of pressurized high temperature electrolyser with concentrated solar tower technology is studied. As the high temperature electrolyser requires constant temperature conditions, the focus is made on a molten salt solar tower due to its high storage capacity. A flowsheet was developed and simulations were carried out with Aspen Plus 8.4 software for MW-scale hydrogen production plants. The solar part was laid out with HFLCAL software. Two different scenarios were considered: the first concerns the production of 400 kg/d hydrogen corresponding to mobility use (fuel station). The second scenario deals with the production of 4000 kg/d hydrogen for industrial use. The process was analyzed from a thermodynamic point of view by calculating the overall process efficiency and determining the annual production. It was assumed that a fixed hydrogen demand exists in the two cases and it was assessed to which extent this can be supplied by the solar high temperature electrolysis process including thermal storage as well as hydrogen storage. For time periods with a potential over supply of hydrogen, it was considered that the excess energy is sold as electricity to the grid. For time periods where the hydrogen demand cannot be fully supplied, electricity consumption from the grid was considered. It was assessed which solar multiple is appropriate to achieve low consumption of grid electricity and low excess energy. It is shown that the consumption of grid electricity is reduced for increasing solar multiple but the efficiency is also reduced. At a solar multiple of 3.0 an annual solar-to-H₂ efficiency greater than 14% is achieved at grid electricity production below 5% for the industrial case (4000 kg/d). In a sensitivity study the paramount importance of electrolyser performance, i.e. efficiency and conversion, is shown.     

SPHD热轧酸洗深冲板轧制工艺研究

研究了CSP工艺制度对热轧酸洗深冲板SPHD力学性能的影响。结果表明,采用50%粗轧大压下量,终轧温度为900℃、终轧压下量小于18%,卷取温度为630℃,分段冷却,在热连轧过程中投入辊缝润滑,可有效降低材料的屈强比,提高深冲性能。     

邯钢CSP连铸机的技术创新与生产实践

介绍了邯钢CSP连铸机十多年的生产实践以及通过持续不断的技术创新,使技术装备和功能应用依然保持了较好的状态,并探索出一套符合该生产线实际的工艺技术,创造性地发展了CSP连铸技术,取得了良好的效果。     

薄板坯连铸连轧30CrMo钢的热轧组织与力学性能

利用光学显微镜、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉伸试验机和硬度仪分析了薄板坯连铸连轧生产的30CrMo钢的热轧微观组织和力学性能。结果表明,该钢主要由珠光体和铁素体组成,珠光体的表观片层间距在0.5μm以下,铁素体晶粒尺寸在5μm以下。该钢热轧屈服强度为461 MPa,抗拉强度达677 MPa,硬度为96.8 HRB,伸长率达23%。与传统厚板坯连铸工艺生产的30CrMo钢热轧组织比,CSP工艺生产的30CrMo钢的组织更细小,综合性能更优良。