影响冰蓄冷空调方案选择的主要因素

通过对某地铁车站采用冰蓄冷空调系统与常规空调系统设备初投资、运行费用、占用面积空间和设备增加回收期的比较分析,探讨影响冰蓄冷空调系统方案选择的因素,得出建筑的冷负荷分布、电价峰谷时间的分布、分时电价及设备占用建筑空间为主要影响因素。     

家用小型中央空调的行业现状分析与展望

介绍了家用小型中央空调的基本原理和系统型式,以及美国、日本和中国各自发家用小型中央空调的技术路线.在分析我国家用小型中央空调发展现状的基础上,结合中国国情特点,特别是家用空调行业特点,提出了我国发展家用小型中央空调的思路.     

辐射空调方式及其发展方向

介绍了辐射空调方式的系统组成及其发展方向，比较了地板辐射供冷系统与吊顶辐射供冷系统的不同，提出了几个应该深入研究的问题。     

Improved solutions for ill-conditioned problems involved in set-membership estimation for fault detection and isolation

Set-membership (SM) estimation implies that the computed solution sets are guaranteed to contain all the feasible estimates consistent with the bounds specified in the model. Two issues often involved in the solution of SM estimation problems and their application to engineering case studies are considered in this paper. The first one is the estimation of derivatives from noisy signals, which in a bounded uncertainty framework means obtaining an enclosure by lower and upper bounds. In this paper, we improve existing methods for enclosing derivatives using Higher-Order Sliding Modes (HOSM) differentiators combining filtering. Our approach turns the use of high order derivatives more efficiently especially when the signal to differentiate has slow dynamics. The second issue of interest is solving linear interval equation systems, which is often an ill-conditioned problem. This problem is reformulated as a Constraint Satisfaction Problem and solved by the combination of the constraint propagation Forward Backward algorithm and the SIVIA algorithm. The two proposed methods are tested on illustrative examples. The two methods are then used in a fault detection and isolation algorithm based on SM parameter estimation that is applied to detect abnormal parameter values in a biological case study.     

基于可编程芯片的信号调理电路设计

本文介绍了信号调理电路在数据采集和控制系统中的作用,并提出了基于模拟可编程器件的信号调理电路设计的方案。通过PAC-Designer软件进行调理电路的编程,下载到ispPAC20芯片,实现放大、求和、滤波等功能。电路外接器件少,且电路性能优良。     

Effect of conditioning temperature on the strength and permeability of normal- and high-strength concrete

In order to evaluate the effect of the conditioning temperature on strength and permeability properties of concrete a series of compressive, indirect tensile and permeability tests were performed on concretes (designed to have 28-day compressive strengths of 40 and 100 N/mm²) conditioned at temperatures of 85 and 105 °C. The results show that, for both the normal- (NSC) and the high-strength concrete (HSC), comparable 28-day test results were obtained from strength tests performed on concrete conditioned at 85 and 105 °C. The permeability results were also somewhat similar for the two conditioning temperatures, although greater differences than previously reported were observed. Conditioning at both 85 and 105 °C was identified as adequate, with the preferred temperature of conditioning being 105 °C.     

Variations in interfacial properties during cell conditioning and influence of heat-treatment of ionomer on the characteristics of direct methanol fuel cells

Variations in interfacial properties in the anode catalyst layer during cell conditioning were characterized, and influence of the heat-treatment of ionomer on the characteristics of direct methanol fuel cells was investigated in this work. The anode catalyst layer was made by mixing a solvent-substituted Nafion solution with unsupported Pt/Ru black and curing the mixture in an oven with an inert environment. Materials characterization (SEM and optical microscopy) and electrochemical characterization (cell polarization, anode polarization, electrochemical impedance spectroscopy, and CO-stripping cyclic voltammetry) were performed. During cell conditioning, the enhanced kinetics of MeOH electrochemical oxidation and severe limiting current phenomenon are due to the combination of variations in interfacial properties and swelling of ionomer in the anode catalyst layer over time. Ru oxides at the catalyst surface are reduced continuously during cell conditioning. The nearly constant integrated areas under the CO-stripping CV peaks and broadened peak shapes indicate a stable number of Pt/Ru bimetallic alloy surface sites, yet the surface composition distribution is broadened. Heat-treatment influences ionomer crystallinity, altering its swelling behavior and hence affecting the characteristics of the direct methanol fuel cell (DMFC) anode.     

An experimental study on the performance of air/water direct contact air conditioning system

Direct contact air conditioning systems, in which heat and mass are transferred directly between air and water droplets, have many advantages over conventional indirect contact systems. The purpose of this research is to investigate the cooling and heating performances of direct contact air conditioning system for various inlet parameters such as air velocity, air temperature, water flow rate and water temperature. The experimental apparatus comprises a wind tunnel, water spray system, scrubber, demister, heater, refrigerator, flow and temperature controller, and data acquisition system. The inlet and outlet conditions of air and water are measured when the air contacts directly with water droplets as a counter flow in the spray section of the wind tunnel, and the heat and mass transfer rates between air and water are calculated. The droplet size of the water sprays is also measured using a Malvern Particle Analyzer. In the cooling conditions, the outlet air temperature and humidity ratio decrease as the water flow rate increases and as the water temperature, air velocity and temperature decrease. On the contrary, the outlet air temperature and humidity ratio increase in the heating conditions as the water flow rate and temperature increase and as the air velocity decreases.     

现代化住宅暖通空调设计要素

本文以某小区的现代化住宅为例,从其温度标准确定、基于人体热舒适性指标PMV的控制系统、合理选择冷冻机规模、新风量的计算确定等方面来阐述现代化住宅暖通空调设计的要素。     

Chemometric characterisation of the fats released during the conditioning processes of table olives

This work deals with the characterisation of five fat types released during the conditioning process of table olives, pitting green olives (PGF), pitting ripe olives (PRF), pitting/stuffing green olives with vegetable origin products (PSGVF) and pitting/stuffing green olives with animal origin materials (PSGAF) along with the fat collected at the end of the factory sewer (WF). The parameters analysed included: acidity, peroxide value, spectrophotometric measurements (K₂₃₂, K₂₇₀ and ΔK), fatty acid composition of the raw material and the neutral fat, triacylglycerol composition of the neutral fat as well as the proportion and composition of the polar fraction. A chemometric analysis of specific groups of compounds was able to establish differences among the types of fats; the overall analysis showed two major groups: PGF, PRF and PSGVF were only moderately degraded, and PSGAF and WF were highly degraded. The information provided can help industries and authorities to handle these residues properly.