温控一体化热计量系统探讨

介绍了温控一体化热计量系统的构成和在分户供暖中的应用,解决供暖无计量、无温控或有计量、收费难等问题,实现热计量公平。     

浅谈热水供热系统温控与热计量技术问题

本文对热水供热系统温控与热计量技术问题进行了分析，实现供热计量按用热收费必须做到系统温度控制，热计量设备准确，同时用户要能主动节能，按实际所需用热，实现用多少热交多少钱。     

变电站直流系统断路器通断特性测试的意义与应用

笔者针对变电站直流系统断路器通断特性测试的相关规定要求,介绍直流断路器通断特性测试的意义,并通过介绍一种直流断路器通断特性测试仪的设计原理与应用情况,验证变电站直流系统上下级保护元件之间的配合选择的重要性,希望借本文内容,能够帮助相关同行,提高变电站直流系统的运行水平。     

浅析住宅分户热计量

本文对住宅分户热计量系统的形式、计量方式、热价的制定以及应注意的问题等方面的内容进行了介绍。     

浅谈开孔补强的等面积法和压力面积法

本文笔者对压力容器开孔补强的等面积法和压力面积法的补强原理、补强范围、计算过程进行了对比和分析。     

基于感性工学研究的热计量器设计

采用感性工学推论法对热计量器进行感性工学研究,确定0次感性概念为热计量器与居家装饰一体,以此类推,得到热计量器的设计细节。该设计改变了传统的设计理念,将设计分成几个细节,并将一些其他产品的现代元素引入到热计量器的设计中,再根据推论逐渐的展开,该设计对于国家热计量设备的改进具有一定的启发和指导意义。     

采用通段时间热量表法的热计量方法探讨

随着我国城镇居民集中供热的大力发展,热计量采用了多种形式的计量方法。目前市场使用较多的一般分为热量表法和通段时间面积法。如何科学合理地进行热计量是关系民生的重要问题。本文通过探讨采用分户计量的热量表法与通段时间面积法两种方法合二为一,即通段时间热量表法进行供热计量的方法,可实现智能通断,自动控制室内温度,无需人为操作,用户可以自主调节室内温度,科学合理地确定热分配系数,实现公平、科学计量的目的。     

集中供暖的温度控制和热计量技术的分析

在集中供暖过程中,分户热计量是非常重要的一种计量方式,那我主要针对集中供暖中的温度控制和热计量技术进行相应的阐述和分析,希望通过本文的阐述和分析能够有效的为我国的热计量发展贡献力量。     

直线回归的最小面积法

自变量、因变量的不同选择，用传统的最小二乘法得到的回归方程是不同的。提出直线回归的最小面积法解决这一问题，推导了该方法的计算公式并讨论了该方法的一些性质。     

高压开关动特性测试仪合、分闸时间测量准确度校准方法探讨

本文介绍了用数字毫秒仪校准高压开关动特性测试仪合、分闸时间测量准确度的方法、接线示意图.     

Thermal Properties Measurement of Micro-electromechanical System Sensors by Digital Moire Method

Abstract:  The thermal properties of a micro-electromechanical system sensor were analysed by a novel digital moiré method. A double-layer micro-cantilever sensor (60  μ m long, 10  μ m width and 2  μ m thick) was prepared by focused ion beam milling. A grating with frequency of 5000 lines mm⁻¹ was etched on the cantilever. The sensor was placed into a scanning electron microscope system with a high temperature device. The observation and recording of the thermal deformation of the grating were realised in real-time as the temperature rose from room temperature to 300 °C at intervals of 50 °C. Digital moiré was generated by interference of the deformed grating and a digital virtual grating. The thermal properties including strain distribution of the sensor and the linear expansion coefficient of polysilicon were accurately measured by the phase-shifted moiré patterns.     

Measurement of Paint Coating Thickness by Thermal Transient Method

This paper is concerned with the accurate laminary determination of the thickness of coatings on metallic surfaces. The development goal was to devise a system that allows for highly spatially resolved full-frame 2-D scans that conventional systems are not able to provide. Furthermore, it is able to allow for a sufficiently large physical separation between the measuring head and the inspected surface to accommodate industrial environments that provide a high operating velocity and is able to detect quality problems of square millimeter in size. The system consists of a heat source that introduces a thermal transient to the surface layer of the specimen, a thermal imaging system to acquire the time-dependent cooling behavior, and an image processing system to determine thermal parameters indicative of surface quality and/or coating thickness. The results clearly show that a thickness resolution of better than 50 $muhbox{m}$ can reliably be obtained at a scanning velocity of 0.37 m/s, covering a field of view (FOV) of approximately $200 times 140 hbox{mm}^{2}$.      

激光闪射法测试耐火材料导热系数的原理与方法

介绍了激光闪射法测定材料导热系数的理论基础,通过对热扩散系数和比热容计算公式的推导,阐述了该方法的基本原理.以德国耐驰仪器制造有限公司生产的LFA-427型激光闪射导热仪为例,介绍了激光闪射法测定导热系数设备的主要组成,并简要说明了该设备的操作步骤以及计算方法.     

驻点防热材料线烧蚀量实时投影测量

为测量高超声速飞行器驻点区防热材料线烧蚀量,提出了一种烧蚀位置投影测量的光学方法。通过标定相机与模型间的比例系数、采集模型的烧蚀视频以及图像处理等手段获取烧蚀后退量。在2种试验状态下,进行了4类材料的烧蚀测量,实现了频率为25Hz的实时测量,且测量误差小于0.16mm,测量结果可应用于烧蚀分析。     

热探针法测定含湿土壤的导热系数

根据线热源瞬态导热模型,设计制作了用于测定含湿土壤导热系数的热探针,研究了加热功率、加热时间、探针壁厚对导热系数测定的影响。对不同含水量的土壤导热系数进行测定,得出纯土、河沙含水量～导热系数拟合关系式。结果表明,热探针法测定含湿土壤的导热系数具有便捷、准确的特点。     

The Analysis of the Gelling Time of Gelatin by a Thermal Sensor Method

Abstract

It has been known that the setting time of gelatin solution may be measured readily by the thermal sensor method. The relation between the setting time (t), the solution concentration (C) and the cooling temperature (T) could be represented empirically as In$$t=a?{(C/T)}^{?1}+b.$$ (a,b: the coefficients). In the present paper, the relation of these three factors is re-examined and the following empirical formula proposed.

$$t=a?{(C/T)}^{?1}+b.$$

This equation is applied to two types of the 4th IAG gelatins (M-8929, PB-1185) to find their gelling characteristics and the correlation between the t-value and the C/T value. This empirical formula could consequently be employed in the study of these relationships for gelatin solution concentrations in the range 4 % to 10 %.     

Measurement of Thermal Diffusivity of Thermal Control Coatings by the Flash Method Using Two-Layer Composite Sample1

The thermal diffusivity of brittle coatings cannot be measured by the flash method directly because of the difficulty of preparing free-standing samples. Adopting the flash method using a two-layer composite sample, it is possible to measure thermal diffusivity if the radiant pulse is well defined and good thermal contact on the interface of the composite sample can be ensured. Using an equilateral trapezoidal pulse of an Nd-glass laser measuring the dimensionless temperature history of the rear face of the sample, we determined the thermal diffusivity of thermal control coatings in the temperature range of 80 to 200°C. The results for different thicknesses of substrate showed that the thermal contact resistance of the interface can be neglected.     

Measurement of the Component-by-Component Flow Rate of a Gas-Liquid Medium by the Thermal Method

Measurement Techniques - The issue of the measurement of a gas-liquid medium by the mass component-by-component flow rate is examined. A thermal method is proposed for measurement of the...     

微电流测量方法探讨

本文介绍了微电流的主要的几种测量方法,包括高阻抗负反馈运放放大法、开关电容积分法、运算放大器I-F转换换法、运放差分电路I-V变换法。详细的分析了各个测量方法的电路构成和放大转换原理,同时对各测量方法的优、缺点进行和各自不同的适用场合进行了比较。本文分析为研究和研制电路较简单、精度较高、成本较低、寿命较长的微电流检测仪器具有比较现实的指导作用。