Convective hot-air chambers impulse drying of pear wood lumbers

A review of literary sources on the physical and mechanical properties of pearwood and its use as structural elements of furniture is given. The aerodynamic chambers, their advantages and disadvantages, as well as their modernization are considered. The use of impulse modes for drying hardwood is substantiated, including sawn timber from pear wood 50 mm thick, pilot drying of which began in the modernized URAL-72 chamber in 1999 at Intar LLC, Moscow. The moisture content of the wood samples and the value of internal stresses were controlled in accordance with GOST 16588. The process of impulse drying included from 9 to 12 steps, the temperature at the operating stage ranged from 45 °C to 72 °C. It has been proved that the use of pulse modes for drying pear timber saves up to 30% of electricity.

BIM-MODEL USAGE FOR TECHNICAL OPERATION OF BUILDING ENGINEERING SYSTEMS

Subject of the study: This article explores modern methods of technical operation of building engineering networks, problems faced by operating organizations and possible ways to solve them out in the future using BIM technologies. Purpose: Setting the concept problem of the technical operation of buildings and solving it by different way using modern BIMtechnologies. Considering the benefits of this approach. Materials and methods: Information and materials provided by manufacturers of automated dispatch and management systems, as well as software by Autodesk, were used for the present research. Results: The concept of using BIMtechnologies for objects of the capital constructions at the operating stage was stated by the authors. Conclusions: The main advantages of the proposed concept are given over the existing approaches.

Delamination Detection in Polymeric Ablative Materials Using Pulse-Compression Thermography and Air-Coupled Ultrasound

Ablative materials are used extensively in the aerospace industry for protection against high thermal stresses and temperatures, an example being glass/silicone composites. The extreme conditions faced and the cost-risk related to the production/operating stage of such high-tech materials indicate the importance of detecting any anomaly or defect arising from the manufacturing process. In this paper, two different non-destructive testing techniques, namely active thermography and ultrasonic testing, have been used to detect a delamination in a glass/silicone composite. It is shown that a frequency modulated chirp signal and pulse-compression can successfully be used in active thermography for detecting such a delamination. Moreover, the same type of input signal and post-processing can be used to generate an image using air-coupled ultrasound, and an interesting comparison between the two can be made to further characterise the defect.

Research for Framework of BIM-Based Platform on Facility Maintenance Management on the Operating Stage in Metro Station

Facility management in metro station is an important content of the operation stage, relates to people's daily travel safety, and needs to be more efficient and reliable. At present, the research and application of BIM in the design and construction stage has made great progress in the domestic, but the research of BIM in operation stage is still in the exploratory stage. Through the investigation, this study analyzed the demand of the facility management in metro station, proposed data requirements to build operation model of a metro station, established a framework of BIM-based platform on facility maintenance management in metro station, and expected to provide a more efficient and reliable digital means for facility management in metro station. The results of this study were applied in a metro station in Shanghai, and obtained the ideal effect.

Fabrication and Performance of La0.6Sr0.4Co0.2Fe0.8O3−δ Infiltrated-Yttria-Stabilized Zirconia Cathode on Anode-Supported Solid Oxide Fuel Cell

The three layers with porous yttria-stabilized zirconia (YSZ) backbone/dense YSZ/porous NiO–YSZ were fabricated by tape-casting process, respectively, then laminated together and co-fired at 1300 °C for 5 h. The cathode material La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) was loaded by infiltrating the precursor of metal ions into porous YSZ backbone. As a result, LSCF nanoparticles with the size of 60–100 nm were uniformly distributed on YSZ backbone. The power density was 1.046 W cm−2 and the polarization resistance was 0.17 Ω cm2 at 800 °C in humidified H2 (3 vol.% H2O). But the stability was not good enough, especially in early operating stage, e.g., 20 h. After that, it showed good stability for the following 70 h operating under a constant voltage of 0.7 V at 750 °C. This is due to the growth and agglomeration of LSCF nanoparticles at early steps, which reduced the three phase boundaries (TPBs).

Stress Analysis on a Weld Seam between Spiral Case and Penstock

Prototype observation and finite element analysis were carried out on a weld seam between a spiral case and a penstock of #6 generator in a certain power plant. According to the observation data and finite element calculated results, deformation and stress were analyzed for the weld seam in continuous operating stage (power generation, EL. 206.00). The results show that in the normal operation power generation stage, the strengths of the penstock, the spiral case and the weld seam are all satisfied; Even if the inlet water level reaches to EL. 275.00, the three parts are all safe (when the residual stress isn’t considered, the stress is far lower than the strength allowed values). However, the stress at point E is obviously higher, it is necessary to make further testing inspection. Finally the following suggestions are given: (1) the strain gauges should be arranged both circumferentially and axially, this is because the circumferential stress of weld seam is greater than axial stress; (2) the stiffener rings should be moved left by 50mm, thus the axial stress can be minimized and the circumferential stress can also be reduced.

Study on Operation and Control of Large Multi-Chiller System

In semiconductor factories and electronics factories, a large multi-chiller system is needed to satisfy strict cooling load requirements. In order to save energy, it is worthwhile to design the chilled water system operation. In this paper, a design methodology is developed for multi-chiller system in which chiller units consist of different cooling capacities chiller that run in parallel. The optimal design problem can be expressed as a mixed integer nonlinear programming (MINLP) which minimizes the system energy consumption within a future time period. In order to solve this complex problem, the two-stage strategy is employed to divide the problem into a scheduling stage and an operating stage. Instead of a lag scheme obtained with general method, this forecasting scheme consists of a series of optimal scheme at each sub-time period and can offer operating reference for operator. The effectiveness of the proposed method is illustrated by an industrial case

Active Control and Energy Cost Assessment of a Rotating Machine

The performances for controlling a rotating machine by using either an Electromagnetic Actuator or a Piezoelectric Actuator are compared in this work. The aim is to establish selection criteria based on environmental impact. Life Cycle Analysis shows that the operating stage has a considerable impact. In this study, only the operating stage is considered. The energy consumed by the actuators seems to be the appropriate indicator for the same "mechanical" performances. Numerical studies are carried out in order to quantify the energy consumed in each case. Modal control strategy with a fuzzy controller is used. The controller inputs are displacements and velocities. The system studied is modeled by using finite element method and the electrical circuit of each actuator is modeled by using basic electricity and electromagnetism theories. Several configurations are assessed and defined by using the chosen Functional Unit.The results obtained show that both controllers are efficient and enable recommendations for optimal control procedures design for the energy consumed.